arrow
arrow
arrow
Select the number from among the given options that can replace the question mark (?) in the following series.8, 17, 35, 71, ?
Question

Select the number from among the given options that can replace the question mark (?) in the following series.
8, 17, 35, 71, ?

A.

141

B.

133

C.

143

D.

142

Correct option is C

Given8, 17, 35, 71, ?
Logic: (Previous Number ×\times 2) + 1 = Next Number given series.
×\times​ 2 = 16, 16 + 1 = 17
17 ×\times 2 = 34, 34 + 1 = 35
35 ×\times​ 2 = 70, 70 + 1 = 71
Similarly,
71 ×\times​ 2 = 142, 142 + 1 = 143
Thus, correct option is (c).

Free Tests

Free
Must Attempt

CBT-1 Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

RRB NTPC Graduate Level PYP (Held on 5 Jun 2025 S1)

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

CBT-1 General Awareness Section Test 1

languageIcon English
  • pdpQsnIcon40 Questions
  • pdpsheetsIcon30 Marks
  • timerIcon25 Mins
languageIcon English
test-prime-package

Access ‘RRB NTPC’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
354k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow