Question

A card is drawn at random from a pack of 100 cards numbered 1 to 100. The probability of drawing a number which is a square is

• A. $\frac{1}{5}$
• B. $\frac{2}{5}$
• C. $\frac{1}{10}$
• D. none of these

Answer 1

The correct option is C

$\frac{1}{10}$

Clearly, the sample space is given by

S = \{1, 2, 3, 4, 5, ....., 97, 98, 99, 100\}

$\therefore n\left(S\right)=100$

Let E = event of getting a square.

Then E = \{1, 4, 9, 16, 25, 36, 49, 64, 81, 100\}

$\therefore n\left(E\right)=10$

Hence. required probability $=\frac{n\left(E\right)}{n\left(S\right)}$

$=\frac{10}{100}=\frac{1}{10}$