Question

A boy tosses a fair coin 3 times. If he gets ₹ 2x for x heads then his expected gain equals ₹ ______

विकल्प

• 1

• `3/2`

• 3

• 4

Answer 1

A boy tosses a fair coin 3 times. If he gets ₹ 2x for x heads then his expected gain equals ₹ 3.

Explanation:

y = 2x

x	0	1	2	3
y	0	2	4	6
P(y)	`1/8`	`3/8`	`3/8`	`1/8`

∴ Expected gain = `sumy_iP(y_i)`

= `0(1/8) + 2(3/8) + 4(3/8) + 6(1/8)`

= 3