Question

An urn contain $25$ tickets from $1$ to $25$. A person is given two chance to drawn two tickets one by one. If the tickets number bear the multiple of $7$ he wins a gift voucher of Rs. $10000$. What is the probability that a person will win two gift vouchers if the tickets are replaced after every draw?

• A. $\frac{1}{625}$
• B. $\frac{3}{625}$
• C. $\frac{6}{625}$
• D. $\frac{5}{625}$

Answer 1

The correct option is C $\frac{6}{625}$

Given: an urn containing $25$ tickets, two tickets are drawn with replacement

To find: the probability that a person will win two gift vouchers

Sol: According to the question,

$n\left(S\right)=25$

Multiple of $7$ between $1$ to $25$ are $\{7,14,21\}=3$

Hence the probability that a person will win two gift vouchers is nothing but the probability that a person will get multiple of $7$ two times.

Therefore the required probability is

$\frac{3}{25}\times \frac{3}{25}=\frac{6}{625}$