Question

The probability that bomb will miss the target is 0.2. Then, the probability that out of 10 bombs dropped exactly 2 will hit the target is ____________.

Options

• `288/5^9`

• `144/5^10`

• `288/5^10`

• `144/5^9`

Answer 1

The probability that bomb will miss the target is 0.2. Then, the probability that out of 10 bombs dropped exactly 2 will hit the target is `underline(144/5^9)`.

Explanation:

Here, n = 10, p = 0.8, q = 0.2, r = 2

∴ Required probability = `""^10"C"_2 (0.8)^2 (0.2)^8`

= `""^10"C"_2 (4/5)^2 (1/5)^8`

= `(45 xx 16)/5^10`

= `(9 xx 16)/5^9`

= `144/5^9`