Question

A fair coin is tossed 5 times in a row. The exact probability of the coin landing heads exactly 2 times is

Answer 1

Answer: $\frac{5}{16}$

Step-by-step explanation:

Given: A fair coin is tossed 5 times in a row.

Total outcomes=2×2×2×2×2=32 [total outcomes in a coin is 2]

Let A be the event of getting heads exactly 2 times

Then the favorable outcomes=$^5C_2$

$=\frac{5!}{2!(5-2)!}=\frac{5\times4\times3!}{2!\times3!}\\=\frac{5\times4}{2}=10$

Then probablity of getting heads exactly 2 times =

$P(A)=\frac{\text{Number of favorable outcomes}}{\text{Total outcomes}}\\\Rightarrow\ P(A)=\frac{10}{32}\\\\\Rightarrow\ P(A)=\frac{5}{16}$

Answer 2

Answer:

Step-by-step explanation:

2×2×2×2×2=32