Question

Two bulbs are chosen at random from 10 bulbs, of which 4 are defective. These two bulbs are fitted in a room, the chance of the room being lighted is?
1. 13/15
2. 11/15
3. 12/13
4. 11/13

Answer 1

Correct Answer - Option 1 : 13/15

Given:

The total bulbs are 10

Calculation:

⇒ Probability of the room not being lighted = ⁴C₂/¹⁰C₂ 

⇒ Probability of being lighted = 1 - 4C2/10C₂ = 13/15

∴ The required result will be 13/15.