Directions (1-5): What should come in place of the question mark (?) in the following number series?
1. 7 5 7 17 63 ?
a) 308
b) 302
c) 309
d) 409
e) 390
2. 50 ? 61 89 154 280
a) 52
b) 51
c) 60
d) 62
e) 60
3. 17 19 25 37 ? 87
a) 47
b) 37
c) 57
d) 67
e) 75
4. 11 14 19 28 43 ?
a) 55
b) 44
c) 77
d) 88
e) 66
5. 26 144 590 1164 ?
a) 1296
b) 1182
c) 2059
d) 1182
e) 1181
Answers:
1. c) 309
Solution:
7 x 1 – 2 = 5
5 x 2 – 3 = 7
7 x 3 – 4 = 17
17 x 4 – 5 = 63
63 x 5 – 6 = 309
7 x 1 – 2 = 5
5 x 2 – 3 = 7
7 x 3 – 4 = 17
17 x 4 – 5 = 63
63 x 5 – 6 = 309
2. a) 52
Solution:
50..50+(1^3+1) = 52
52+(2^3+1)=61.
61+(3^3+1)=89
89+(4^3+1)=154
154 + (5^3+1) = 280
50..50+(1^3+1) = 52
52+(2^3+1)=61.
61+(3^3+1)=89
89+(4^3+1)=154
154 + (5^3+1) = 280
3. c) 57
Solution:
17 + 1 x 2 = 19
19 + 2 x 3 = 25
25 + 3 x 4 = 37
37 + 4 x 5 = 57
57 + 5 x 6 = 87
17 + 1 x 2 = 19
19 + 2 x 3 = 25
25 + 3 x 4 = 37
37 + 4 x 5 = 57
57 + 5 x 6 = 87
4. e) 66
Solution:
3….5...9...15...23
…2....4....6....8…
3….5...9...15...23
…2....4....6....8…
Answer 43+23= 66
5. b) 1182
Solution:
26 x 6 – 12 = 144
144 x 4 + 14 = 590
590 x 2 – 16 = 1164
1164 x 1 + 18 = 1182
26 x 6 – 12 = 144
144 x 4 + 14 = 590
590 x 2 – 16 = 1164
1164 x 1 + 18 = 1182
Thanks.
