Question

The probability of an arrow reaching a target is 0.85. How many times the arrow must be shot in order to hit the target 340 times?

• A. $289$
• B. $400$
• C. $500$
• D. $600$

Answer 1

The correct option is B $400$

The probability of arrow reaching the target $=0.85$

The probability that no arrow hits the target $=0.15$

$\Rightarrow P$ (arrow hitting) $=\frac{85}{100}$

Which means that $85$ of every $100$ arrows hit the target and $15$ of every $100$ arrows does not hit the target.

Given that the target was hit $340$ times.

$\therefore 85\times 4=340$ times and the no. of shots missed $15\times 4=60.$

$\therefore 340+60=400.$

Hence, the answer is $400.$