Which of the following number will replace the question mark (?) in the given series ?
8, 18, 38, 78, 158, ?
a) 290
b) 340
c) 268
d) 318
Ans : d) 318
SSC GD 20 Feb Shift I
Solution :
Series : 8, 18, 38, 78, 158, ?
Difference 10, 20, 40, 80, 160 (Next difference is multiply by 2)
Add 160 in 158 for next term = 318