Question

In tossing 8 coins, the probability of getting exactly 3 tails is ______

Options

• `7/256`

• `1/32`

• `1/256`

• `7/32`

Answer 1

In tossing 8 coins, the probability of getting exactly 3 tails is `underline(7/32)`.

Explanation:

The probability of getting tail is p = `1/2`

∴ q = `1 - 1/2 = 1/2`

Also, n = 8

∴ Required probability = P (X = 3)

= `""^8"C"_3(1/2)^3(1/2)^5`

= `7/32`