Here some examples (quite all solved):
| #M400 | Question | Link | Reasoning | Answer |
|---|---|---|---|---|
| M40013758 | 49,7,98,16,4,48,9,3,36,25,5,? | http://www.m4maths.com/13758-49-7-98-16-4-48-9-3-36-25-5.html | Knot Group by 3: x^2,x,n*x^2; n= 2 (49,7,98), 3 (16,4,48), 4 (9,3,36), 5 (25,5,?) |
125 |
| M40013757 | 8,0.5,16,4,15,0.3,50,4.5,6,0.2,30,? | http://www.m4maths.com/13757-8-0-5-16-4-15-0-3-50-4-5-6-0-23-30.html | Group by 4: x,y,(x/y),(x*y) 8,0.5,16,4 15,0.3,50,4.5 6,0.2,30,? |
1.2 |
| M40013756 | 49,6,25,4,36,5,81,8,? | http://www.m4maths.com/13756-49-6-25-4-36-5-81-5.html | Chain Group by 2: (x+1)^2,x; x=6,4,5,8,…,?; Link=? 6-4=2; 4-5=-1;5-8=-3;8-4=4 |
16 |
| M40013736 | 3,2,1,4,5,4,1,0,6,3,? | http://www.m4maths.com/13736-3-2-1-4-5-4-1-0-6-3.html | Group by 4: x,y,(x-y),z; 3,2,1,4; 5,4,1,0; 6,3,?,… |
3 |
| M40013735 | 33,8,41,46,21,67,72,47,119,124,? | http://www.m4maths.com/13735-33-8-41-46-21-67-72-47-119-124.html | Chain Patterned Group by 3: x,y(=x-25),z(=2x-25); Chain: a=z+5 33,8,41; 46,21,67; 72,47,119; 124,?,223 |
99 |
| M40013734 | 9,4,16,6,36,21,441,? | http://www.m4maths.com/13734-9-4-16-6-36-21-441.html | Chain Pattern Group by 2: x,(x-n5),(x-n5)^2 n=1(9,4,16),2(16,6,36),3(36,21,441),4(441,?,…) |
421 |
| M40013732 | -16,-8,4,24,12,-6,-40,? | http://www.m4maths.com/13732--16--8-4-24-12--6--40.html | Chain Patterned Group by 3: x,(x/2),(-x/4) -16,-8,4; 24,12,-6; -40,?,10 |
-20 |
| M40013730 | 52,62,42,78,89,68,49,61,39,63,76,? | http://www.m4maths.com/13730-52-62-42-78-89-68-49-61-39-63-76.html | Knot Patterned Group by 3: x,(x+10+n),(x-10); Knot:n n=0:52,62,42; n=1:78,89,68; n=2:49,61,39; n=3:63,76,? |
53 |
| M40013729 | 9,3,24,4,9,3,36,6,9,3,30,? | http://www.m4maths.com/13729-9-3-24-4-9-3-36-6-9-3-30.html | Group by 4: 9,3,x,(x/6); 9,3,24,4; 9,3,36,6; 9,3,30,?; |
5 |
| M40013700 | -3,-4,-9,-28,?? | http://www.m4maths.com/13700--3--4--9--28.html | Group by 2:x,(x*n-1); n=1(-3,-4),2(-4,-9),3(-9,-28),4(?,…) |
-113 |
| M40013692 | 30.5,31,30.0,67,? | http://www.m4maths.com/13692-30-5-31-30-0-67.html | Group by 3: x,(x+0.5),(x-05); x=30.5(30.5,31,30),67(67,?,…) |
67.5 |
| M40013691 | 67,70,100,183.9,? | http://www.m4maths.com/13691-67-70-100-183-9.html | Unique: x,round(x),re-round(x) | 184 |
| M40013690 | 5,16,22,68,28,87,34,106,11,? | http://www.m4maths.com/13690-5-16-22-68-28-87-34-106-11.html | Knot Patterned Group by 2: x,(3x+n); n=1(5,16),2(22,68),3(28,67),4(34,106),5(11,?) |
38 |
| M40013689 | 27,16,10,9,? | http://www.m4maths.com/13689-27-16-10-9.html | Unique: x,(x-n5-1); n=2(27,16),1(16,10),0(10,9),-1(9,?) |
13 |
| M40013676 | 5,6,6.5,6.5,8,7,9.5,? | http://www.m4maths.com/13676-5-6-6-5-6-5-8-7-9-5.html | 2 Parallel Knots: x,y,(x+1.5*n),(y+0.5*m); n=1(6.5),2(8),3(9.5); m=1(6.5),2(7),3(?) |
7.5 |
| M40013675 | 0,1,2,0.5,2,2,2,2,4,3,2,? | http://www.m4maths.com/13675-0-1-2-0-5-2-2-2-2-4-3-2.html | 4 Parallel Knots: x,y,z,w; (x+2n); (y+n); (z+0); (w+1.5n); x=0,2,4 y=1,2,3 z=2,2,2 w=0.5,2,? |
3.5 |
| M40013674 | 56,89,33,21,57,88,35,19,60,85,39,15,65,? | http://www.m4maths.com/13674-56-89-33-21-57-88-35-19-60-85-39-50-65.html | Group by 4: x,(145-x),y,(54-y); 56,89,33,21; 57,88,35,19; 60,85,39,15; 65,?,...; |
80 |
| M40013673 | 96,64,128,192,128,256,288,192,? | http://www.m4maths.com/13673-96-64-128-192-128-256-256-288-192.html | Patterned Group by 3: (x*1.5),x,(x*2); otherwise: x,y,z x,2x,3x,… (x=96); y,2y,3y,… (y=64); z,2z,3z,… (z=128); |
384 |
| M40013672 | 9,15,26/3,29/2,25/3,14,8,27/2,? | http://www.m4maths.com/13672-9-15-26-3-29-2-25-3-14-8-27-2.html | 2 Parallel: x,y,(x-1/3),(y-1/2),… x=9,26/3,25/3,24/3(=8),?; y=15,29/2,28/2(=14),27/2; |
23/3 |
| M40013671 | 1,2,3,6,11,20,37,68,? | http://www.m4maths.com/13671-1-2-3-6-11-20-37-68.html | Unique: x,y,z,(x+y+z),…; ?=20+37+68 |
135 |
| M40013670 | 12,48,96,384,768,3072 | http://www.m4maths.com/13670-11-48-100-384-768-3072.html | Unique: x,(4*x),(2*4*x),(4*2*4x),... x,4x),8x,32x,64x,256x,?; |
6144 |
| M40013664 | 3,2,1,4,5,1,0,6,3,? | http://www.m4maths.com/13664-3-2-1-4-5-1-0-6-3.html | 3 Parallels: x,y,z; x=3,4,5,6; y=2,5,1,3; z=1,4,0,? |
2 |
| M40013664 | 1,3,3,2,8,10,3,4,12,4,8,? | http://www.m4maths.com/13663-1-3-3-2-8-10-3-4-12-4-8.html | Group by 3: 'x,y,(x*y) and z,w,(z+w) 4,8,?(=4+8) |
12 |
| M40013662 | 2,9,5,49,11,169,? | http://www.m4maths.com/13662-2-9-5-49-11-169.html | Unique: Sequence of Prime Numbers: x,y^2,z,w^2,... 2,(3^2),5,(7^2),11,(13^2),? |
17 |
| M40013661 | 1,1,1,2,2,2,3,4,3,3,5,6,? | http://www.m4maths.com/13661-1-1-1-2-2-2-3-4-3-3-5-6.html | Group by 3: since each number repeats 3 times and there is only one 4. | 4 |
| M40013660 | 1/4,1/4,1/2,1.50,6,? | http://www.m4maths.com/13660-1-4-1-4-1-2-1-2-1-50-6.html | Knot Unique: x,(x*n),…; 6*5=30 |
30 |
| M40013659 | 9,4,16,6,36,21,44,? | http://www.m4maths.com/13659-9-4-16-6-36-21-44.html | Knot Group by 2: x,(x-5n); n=1(9,5),2(16,6),3(36,21),4(44,?) |
24 |
| M40013658 | 2,6,5,11,26,17,? | http://www.m4maths.com/13658-2-6-5-11-26-17.html | Chain Patterned Group by 3: x,(2x+n),(x+n); (y+z) '2,(2*2+2),(2+3); 11,(11*2+4),(11+5),? |
43 |
| M40013645 | 1370,1320,1070,-180.? | http://www.m4maths.com/13645-1370-1320-1070--180.html | Unique: x,(x-10*5^n); n=1(50: 1370,1320),2(250:1320,1070),3(1250:1070,-180),4(6250:-180,?) |
-6430 |
| M40013644 | 3,2,1,4,5,4,5,1,0,6,3,? | http://www.m4maths.com/13644-3-2-1-4-5-4-5-1-0-6-3.html | 3 Parallels: x,y,z; x=3,4,5,6; y=2,5,1,3; z=1,4,0,? |
2 |
| M40013643 | 4,2,5,9,5,11,13,7,16,17,9,? | http://www.m4maths.com/13643-4-2-5-9-5-11-13-7-16-17-9.html | Group by 3: x,y,(x+n); n=1(4,2,5),2(9,5,11),3(13,7,16),4(17,9,?) |
21 |
| M40013641 | 8,0.5,16,4,15,0.3,50,4.5,6,0.2,30,? | http://www.m4maths.com/13641-8-0-5-16-4-15-0-3-50-4-5-6-0-2-30.html | Group by 4: x,y,(x/y),(x*y) 8,0.5,16,4 15,0.3,50,4.5 6,0.2,30,? |
1.2 |
| M40013630 | 3.274,3.2744,3.3184,? | http://www.m4maths.com/13630-3-274-3-2744-3-3184.html | Unique: x,(x+0.0004),(x+0.0004+0.0044),? | 3.3628 |
| M40013630 | 0.8,0.3,0.5,0.5,0.25,0.25,0.8,0.16,0.6,0.5,0.3,? | http://www.m4maths.com/13612-0-8-0-3-0-5-0-5-0-25-0-25-0-8-0-16-0-6-0-5.html | Group by 3: x,y,round(x-y); 0.8,0.5,0.3; 0.5,0.25,0.25 0.8,0.16,0.6 0.5,0.3,? |
0.2 |
| M40013611 | 1,1,1,2,2,2,3,4,4,4,5,6,? | http://www.m4maths.com/13611-1-1-1-2-2-2-3-4-4-4-5-6.html | Group by 4: x,x,x,(x+1); 1,1,1,2 2,2,3,4 5,6,? |
6 |
| M40013610 | 5,1,2,3,1,0,9,2,3,14,1,3,? | http://www.m4maths.com/13610-5-1-2-3-1-0-9-2-3-14-1-3.html | ||
| M40013597 | 340,680,1428,3146.6,? | http://www.m4maths.com/13597-340-680-1428-3146-6.html | Unique: x,(x*2),(x*2*2.1),(x*2*2.1*2.2),… 3146.6*2.3=? |
7225.68 |
| M40013596 | 3.2, 14.23, 7, 5.2, 12.03, 8, 7.2, 9.83, 9,? | http://www.m4maths.com/13596-32-14-23-7-5-2-12-03.html | Group by 3: x,y,z; x=3.2, 5.2, 7.2, 9.2 |
9.2 |
| M40013595 | 4,3,6,5,11,10,19,18,30,29,.....? | http://www.m4maths.com/13595-4-3-6-5-11-10-19-18-30-29.html | Chain Patterned Group by 2: x,(x-1); and y=(x+3+2n); n=0: 4,3; 6,5; n=1: 6,5; 11,10; n=2: 11,10; 19,18 n=3: 19.18; 30,29; n=4: 30,39; ? |
44 |
| M40013594 | 1/2,5/4,2,11/4,7/2 .....? | http://www.m4maths.com/13594-1-2-5-4-2-11-4-7-2.html | Unique: 'x=(2+3n)/4 | 17/4 |
| M40013593 | 7776,625,64,9..............? | http://www.m4maths.com/13593-7776-625-64-9.html | Unique: 'x^(x-1) | 2 |
| M40013593 | 507,169,248,62,36,12,168,42,168,? | http://www.m4maths.com/13536-507-169-248-62-36-12-168-42-168.html | Group by 4: x,(x/3),y,(y/4) | 56 |
| M40013534 | 9,12,4,8,12,15,5,9,3,6,2,6,6,9,? | http://www.m4maths.com/13534-9-12-4-8-12-15-5-9-3-6-2-6-6-9.html | Group by 4: x, (x-3),(x-3)/3,(x-3)/3+4 9, 12, 4, 8 12,15, 5, 9 3, 6, 2, 6 6, 9, ?, 7 |
3 |
| M40013533 | 7,4,6,3,4.5,1.5,2.25,-0.75 | http://www.m4maths.com/13533-7-4-6-3-4-5-1-5-2-25--0-75.html | Patterned Chain Group by 2: x,(x-3); and y=(x+1.5^n) n=0: 7,6 n=1: 6,4.5 n=2: 4.5,2.25 n=3: 2.25,? |
-3.375 |
| M40013532 | 7,-14,-4,15,-30,-20,-21 | http://www.m4maths.com/13532-7--14--4-15--30--20--21.html | Group by 3: x,(x*-2),(x*-2+10) | 42 |
| M40013530 | 3.2,4.2,4.7,2.7,6.2,1.2,7.7,-0.3,9.2,-1.8 | http://www.m4maths.com/13530-3-2-4-2-4-7-2-7-6-2-1-2-7-7--0-3-9-2--1-8.html | 2 Parallel series: 3.2,4.7,6.2,7.7,9.2,? 4.2,2.7,1.2,-0.3,-1.8,… |
10.7 |
| M40013529 | 41.45,41.5,42,18.23,18.2,18,73.0 | http://www.m4maths.com/13529-41-45-41-5-42-18-23-18-2-18-73-09.html | Group by 3: 'Progressive Rounding 41.45,41,5,42 18.23,18.2,18 73.0,? |
75 |
| M40013527 | 7.2,2.2,3.2,16,11,12,60,55,56,? | http://www.m4maths.com/13527-7-2-2-3-2-16-11-12-60-55-56.html | Chain Group by 3: x,(x-5),(x-4); and y=(x-4)*5 56*5=280 |
280 |
| M40013526 | 100,98,95,90,83,? | http://www.m4maths.com/13526-100-98-95-90-83.html | Unique: x, (x-2),(x-2-3),(x-2-3-5),(x-2-3-5-7),… Next prime number is 11 |
72 |
| M40013522 | 1,3,3,2,8,10,3,4,12,4,8,? | http://www.m4maths.com/13522-1-3-3-2-8-10-3-4-12-8.html | Group by 3: x,y,(x*y) and x,y,(x+y) 4+8=12 |
12 |
| M40013521 | 6,18,21,8,11,33,2,6,9,5,8,24,7,21 | http://www.m4maths.com/13521-6-18-21-8-11-33-2-6-9-5-8-24-7-21.html | Group by 3*2: x,(3x),(3x+3) and y,(y+3),3(y+3) 21+3=? |
24 |
| M40013521 | 13,24,36,23,34,56,33,44,96,43,54,156 | http://www.m4maths.com/13469-13-24-36-23-34-56-33-44-96-43-54-156.html | 3 Chain Patterned Parallel: x,(x+11),(x+11+2+10*n); y=x+10 | 53 |
| M40013521 | 5,16,22,68,28,87,34,106,11 | http://www.m4maths.com/13468-5-16-22-68-28-87-34-106-11.html | Patterned Group by 2: x,(x*3+n); n=1: 5,16 n=2: 22,68 n=3: 28,87 n=4: 34,106 n=5: 11,? |
38 |
| M40013467 | +6,-12,+35,+6,-12,-27,+6,-12 | http://www.m4maths.com/13467-6--12-35-6--12--27-6--12.html | Group by 3, dont care about +6,-12. +35,-27,? An answer could be |27-8| with positive sign |
19 |
| M40013467 | 9 18 21 20 25 | http://www.m4maths.com/13448-9-18-21-20-25.html | 2 Parallel Series: 3*3,3*7,5*5,… 3*6,4*5,? |
20 |
| M40013759 | 48,24,35,7,16,8,75,15,80,40,? | http://www.m4maths.com/13759-1-8-0-5-16-4-15-0-3-50-4-5-6-0-2-30-2-9-4-16.html | Chain Group by 4: x,(x/2),y,(y/5) and (x+x/2+y+y/5=114) 48,24,35,7 16,8,75,15 80,40,?,-1 |
-5 |
| M40013411 | 1,3,1,2.5,5,1,4,5,4,8,7,? | http://www.m4maths.com/13411-1-3-1-2-5-5-1-4-5-4-8-7.html | Group by 4: x,y,z,(x+y+z)/2 1,3,1,2.5 5,1,4,5 4,8,7,? |
9.5 |
| M40013410 | 3,2,1,4,5,1,0,6,3,? | http://www.m4maths.com/13410-3-2-1-4-5-1-0-6-3.html | Group by 5: x,y,z,w,(x+y+z+w)/2 3,2,1,4,5 1,0,6,3,? |
5 |
| M40013409 | 10,12,-36,-7,-5,15,19,21,? | http://www.m4maths.com/13409-10-12--36--7--5-15-19-21.html | Group by 3;x,(x+2),(x+2)*-3 10,12,-36 -7,-5,15 19,21,? |
-63 |
| M40013408 | 5,1,2,3,1,0,9,2,3,14,1,3,? | http://www.m4maths.com/13408-5-1-2-3-1-0-9-2-3-14-1-3.html | ||
| M40013378 | 3,3,4,8,10,36,? | http://www.m4maths.com/13378-3-3-4-8-10-36.html | 2 Parallels: x,y,(x*n+n),(y*n+n) 3,4(=3*1+1),10(=4*2+2),? 3,8(=3*2+2),36(=8*4+4),… |
33 |
| M40013377 | 18,20,22,20,28,20,? | http://www.m4maths.com/13377-18-20-22-20-28-20.html | 2 Parallels: x,20,(x+2n),20,… 18,22(=18+2*2),28(=22+3*2),? |
36 |
| M40013376 | 7,6,8,5,3,7,? | http://www.m4maths.com/13376-7-6-8-5-3-7.html | Chain Group by 3: average(x,y),x,y and a=(average(x,y)+x)/3 7,6,8 5,3,7 ?(=4) |
4 |
| M40013241 | 4,5,7,11,16,19,? | http://www.m4maths.com/13241-4-5-7-11-16-19.html | Probably, it should not be 19… If it 23: Unique: x,y,z,(x+z),(x+y+z),(x+y+2z),? ?(=23+11=34) |
34 |
| M40013201 | 4,20,84,340,? | http://www.m4maths.com/13201-4-20-84-340.html | Unique: x,(x+2^2n),… Starting from n=2 4,20(=4+2^4),84(=20+2^6),340(=84+2^8),?(=1364=340+2^10) |
1364 |
| M40012238 | -3,-4,-9,-28,? | http://www.m4maths.com/12238--3--4--9--28.html | Unique: x,(n*x-1) -3,-4(=1*-3-1),-9(=2*-4-1),28(=3*-9,-1),?(=4*-28-1) |
-113 |
| M40012190 | -5,1,-11,23,29,17,-20,-14,? | http://www.m4maths.com/12190--5-1--11-23-29-17--20--14.html | Group by 3: x,y,(x*2-y) -5,1,-11(=-5*2-1) 23,29,17(=23*2-29) -20,-14,?(=-26=-20*2+14) |
-26 |
| M40012189 | 0,1,1,2,0.5,2,2,4,2,2,4,3,7,? | http://www.m4maths.com/12189-0-1-1-2-0-5-2-2-4-2-2-4-3-7.html | Group by 5: x,y,(x+y),2,(x/2+y/2),… 0,1,1,2,0.5 2,2,4,2,2 4,3,7,?(=2),3.5 |
2 |
| M40012175 | 7,0,1,8,5,12,9,26,3,23,2,? | http://www.m4maths.com/12175-7-0-1-8-5-12-9-26-3-23-2.html | Group by 4: x,y,z,(x+y+z) 7,0,1,8 5,12,9,26 3,23,2,?(=28) |
28 |
| M40012174 | 30.5,31,30.0,67.2,67,70,100,183.9,? | http://www.m4maths.com/12174-30-5-31-30-0-67-2-67-70-100-183-9.html | Perhaps lacking some parts… Group by 3: x,round(x),re-round(x) 30.5,31,30 67.2,67,70 100??? 183.9,?(=184) |
184 |
| M40011248 | 49,6,25,4,36,5,81,5,? | http://www.m4maths.com/11248-49-6-25-4-36-5-81-5.html | Group by 2: x^2,(x-1) 7^2,6 5^2,4 6^2,5 9^2,5 |
|
| M40010998 | 1,1,2,4,6,36,39,1521,? | http://www.m4maths.com/10998-1-1-2-4-6-36-39-15-21.html | Unique: x,y(=x^2),z(=y+n),… 1,1(=1^0),2(=1+1),4(=2^2),6(=4+2),36(=6^2),39(=36+3),1521(=39^2),?(=1521+4) |
1525 |
| 1.8,3,0.6,2.5,5,0.5,3.4,2,1.7,4.8,6,? | http://www.m4maths.com/10997-1-8-3-0-6-2-5-5-0-5-3-4-2-1-7-4-8-6.html | Patterned Group by 3: x,y,(x/y) 1.8,3,0.6 2.5,5,0.5 3.4,2,1.7 4.8,6,?(=0.8) |
0.8 | |
| M40010996 | 5,1,2,8,8,1,0,9,9,2,3,? | http://www.m4maths.com/10996-5-1-2-8-8-1-0-9-9-2-3.html | Group by 4: x,y,z,(x+y+z) 5,1,2,8 8,1,0,9 9,2,3,?(=14) |
14 |
| M40010995 | 11.5,17.5,35.5,89.5,? | http://www.m4maths.com/10995-11-5-17-5-35-5-89-5.html | Unique: x,(x+6*3^n) 11.5,17.5(n=0),35.5(n=1),89.5(n=2)?(=251.5,n=3) |
251.5 |
| M40010994 | 12,3,15,14,6,19,16,9,23,18,12,? | http://www.m4maths.com/10994-12-3-15-14-6-19-16-9-23-18-12.html | Knot Group by 3: x,y,(x+y-n) n=0:12,3,15 n=1: 14,6,19 n=2: 16,9,23 n=3: 18,12,?(=27) |
27 |
| M40010993 | 0.8,1.8,3.6,3.6,4.6,9.2,9.2,10.2,? | http://www.m4maths.com/10993-0-8-1-8-3-6-3-6-4-6-9-2-9-2-10-2.html | Patterned Chain Group by 3: x,(x+1),(2x+2); Chain y=2x+2 0.8,1.8,3.6(=2.6+1) 3.6,4.6,9.2(=8.2+1) 9.2,10.2,?(=20.4) |
20.4 |
| M40010992 | 4,2,4,8,6,8,16,? | http://www.m4maths.com/10992-4-2-4-8-6-8-16.html | Patterned Chain Group by 3: x,(x-2),x; Chain y=2x 4,2,4 8,6,8 16,?(=14),16 |
14 |
| M40010991 | 3,4,12,6,1,8,8,4,5,6,30,? | http://www.m4maths.com/10991-3-4-12-6-1-8-8-4-5-6-30.html | Patterned Group by 4: x,y,(x*y),(x*y/2); 3,4,12,6 1,8,8,4 5,6,30,?(=15) |
15 |
| M40010990 | 1/2,1/4,3/4,3/8,7/8,7/16,? | http://www.m4maths.com/10990-1-2-1-4-3-4-3-8-7-8-7-16.html | Double Unique: x,y(=x/2),z(=y+1/2),… 1/2,1/4(=1/2 /2),3/4(=1/4+1/2) 3/4,3/8(=3/4 /2),7/8(=3/4+1/2) 7/8,7/16(=7/8 /2),?(=15/16=7/16+8/16) |
15/16 |
| M400989 | 2,7,-35,7,12,-60,5,10,? | http://www.m4maths.com/10989-2-7--35-7-12--60-5-10.html | Patterned Group by 3: x,(x+5),(y*-5) 2,7,-35 7,12,-60 5,10,?(-50) |
-50 |
| M40010979 | 8,?,16,3 ,27,4,8,7,19,2,0,7 | http://www.m4maths.com/10979-8-16-3-27-4-8-7-19-2-0-7.html | Perhaps to be corrected as: 8,16,3 ,27,4,8,7,19,2,0,7,? Group by 4: x,y,z,(x+y+z) 8,16,3,27 4,8,7,19 2,0,7,?(=9) |
9 |
| M40010965 | 346, 680 ,1428,3141.6, ? | http://www.m4maths.com/10965-346-680-1428-3141-6.html | Patterned Unique: x,(x*2.1),(y*2.2),… 7225.68=3141.6 * 2.3 |
7225.68 |