Question

A box contains tickets, numbered with 11, 12, 13, ...., 40. A ticket is taken out from the box at random. Find the probability that the number on the drawn ticket is greater than 25 and multiple of 7.

• A.
  $\frac{1}{20}$
• B. $\frac{1}{15}$
• C. $\frac{1}{5}$
• D. $\frac{3}{20}$

Answer 1

The correct option is B $\frac{1}{15}$

Total no. of outcomes (count of numbers from 11 to 40)= 30

Outcomes which are divisible by '7' and greater than '25' are 28 and 35.

$\therefore$ Total no. of favourable outcomes= 2

Let $E$ be the event of getting numbers which are divisible by '7' and greater than '25'.

$\text{Probability P(E)}$ = $\frac{\text{Number of outcomes favorable to E}}{\text{Number of all possible outcomes of the experiment}}$

P (number is greater than 25 and multiple of 7 ) $=\frac{2}{30}=\frac{1}{15}$