Question

The probability that a man hits a target is $\frac{3}{4}$.If tried $5$ time, the probability that he will hit the target at least three times,is

• A. $\frac{918}{1024}$
• B. $\frac{884}{1024}$
• C. $\frac{924}{1024}$
• D. $\frac{848}{1024}$

Answer 1

Answer: (A)

$\frac{918}{1024}$

Given, n = 5 and r = 3
Then, Success P = 3/4
Failure, q = 1 - 3/4 = 1/4
Man hit the target thrice
= 5c3$\left({\left(3/4\right)}^3\right)$$\left({\left(1/4\right)}^2\right)$+ 5c4$\left({\left(3/4\right)}^4\right)$(1/4) + 5c3$\left({\left(3/4\right)}^5\right)$
= (270/1024) + (405/1024) + (243/1024)
= 918/1024