Which of the following options will replace the question mark (?) in the given series?
3, 8, 18, 38, ?, 158, 318
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 78.
Given series: 3, 8, 18, 38, ?, 158, 318
3 + 5 = 8; 8 + 10 = 18; 18 + 20 = 38; 38 + 40 = 78; 78 + 80 = 158; 158 + 160 = 318