Question

Find the missing number in the following number series.

6, 5, 8, 21, ?, 395

A.

88

B.

84

C.

81

D.

80

E.

78

Correct option is D


Pattern of series –
6 ×1-1=5
5 ×2-2 = 8
8 ×3-3 =21
21 ×4-4=80
80 ×5-5=395

Free Tests

Free
Must Attempt
Video Solutions

RBI Assistant Pre 2026 Full Mock Test -01

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon60 Mins
languageIcon English
Free
Must Attempt
Video Solutions

RBI Asst Prelims 2026 : Reasoning Section Test 01

languageIcon English
  • pdpQsnIcon35 Questions
  • pdpsheetsIcon35 Marks
  • timerIcon20 Mins
languageIcon English
Free
Must Attempt
Video Solutions

RBI Office Attendant 2026 Full Mock Test - 01

languageIcon English
  • pdpQsnIcon120 Questions
  • pdpsheetsIcon120 Marks
  • timerIcon90 Mins
languageIcon English
test-prime-package

Access ‘IBPS RRB Clerk’ 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