Question

Which of the following are sure events?

• A. Getting a number less than 8 while rolling a dice.
• B. getting heads while tossing a coin.
• C. getting a non face card from a pack of 52 playing cards.
• D. Getting a White ball from a bag which contains 100 black balls.

Answer 1

The correct option is A

Getting a number less than 8 while rolling a dice.

If the probability of occurrence of an event is 1, then such an event is called a sure event.

P(Getting a number less than 8 while rolling a dice)
= $\frac{\text{number of favourable outcomes}}{\text{total number of outcomes}}$
= $\frac{6}{6}$
= 1

P(Getting a head while tossing a coin) is
= $\frac{\text{number of favourable outcomes}}{\text{total number of outcomes}}$
= $\frac{1}{2}$

P(getting a non face card from a pack of 52 playing cards) is
= $\frac{\text{number of favourable outcomes}}{\text{total number of outcomes}}$
= $\frac{40}{52}$
= $\frac{10}{13}$

P(Getting a White ball from a bag which contains 100 black balls) is
= $\frac{\text{number of favourable outcomes}}{\text{total number of outcomes}}$
= $\frac{0}{100}$
= 0

Hence, Getting a number less than 8 while rolling a dice is a sure event