The probability that at least one of the events A and B occur is 0.6. If A and B occur simultaneously with probability 0.2, then the value of P(Ac) + P(Bc) will be

  1. 1.0
  2. 1.1
  3. 1.2
  4. 1.3

Answer (Detailed Solution Below)

Option 3 : 1.2
Free
UPSC NDA 01/2025 General Ability Full (GAT) Full Mock Test
150 Qs. 600 Marks 150 Mins

Detailed Solution

Download Solution PDF

Concept:

Some useful formulas are:

The probability of the complement of an event is one minus the probability of the event.

 We can write, P (A’) or P (Ac) or   = 1 - P (A)

P(A ⋃ B) = P(A) + P(B) - P(A ⋂ B)

Calculation:

P(A) = 1 - P(Ac)

P(B) = 1 - P(Bc)

P(A ⋃ B) = P(A) + P(B) - P(A ⋂ B)

∴ P(A) + P(B) = P(A ⋃ B) + P(A ⋂ B)

∴ [1 - P(Ac)] + [ 1 - P(Bc)] = 0.2 + 0.6

∴ 2 - [P(Ac) + P(Bc)] = 0.8

∴ P(Ac) + P(Bc) = 2 - 0.8 

∴ P(Ac) + P(Bc) = 1.2

Latest NDA Updates

Last updated on Jul 8, 2025

->UPSC NDA Application Correction Window is open from 7th July to 9th July 2025.

->UPSC had extended the UPSC NDA 2 Registration Date till 20th June 2025.

-> A total of 406 vacancies have been announced for NDA 2 Exam 2025.

->The NDA exam date 2025 has been announced. The written examination will be held on 14th September 2025.

-> The selection process for the NDA exam includes a Written Exam and SSB Interview.

-> Candidates who get successful selection under UPSC NDA will get a salary range between Rs. 15,600 to Rs. 39,100. 

-> Candidates must go through the NDA previous year question paper. Attempting the NDA mock test is also essential. 

More Probability of Complementary Event Questions

More Probability Questions

Hot Links: real cash teen patti teen patti palace teen patti game paisa wala teen patti master list teen patti rummy 51 bonus