Question

Which of the following event(s) is/are certain event?

• A. Rising of Sun from the west
• B. Number obtained when we roll a die is less than $7$
• C. Getting head as a result when we toss coin
• D. Getting tail as a result when we toss a coin

Answer 1

The correct option is B Number obtained when we roll a die is less than $7$

The probability of certain events is $1$.

In option (a.), we have "Rising of Sun from the west". We know that Sun rises in the east, hence the probability of this event is $0$. It can not be a certain event.

In option (b.), we have "Number obtained when we roll a die is less than $7$". The possible outcomes when we roll a die are $1,2,3,4,5$ and $6$. Each of these numbers are less than $7$. Hence, the probability of this event is $1$.

In option (c.), we have "Getting head as a result when we toss a coin". When we toss a coin, we can either obtain a head or a tail. The probability of obtaining a head when a coin is tossed is $\frac{1}{2}$, i.e. $0.5$.

In option (d.), we have "Getting tail as a result when we toss a coin". When we toss a coin, we can either obtain a head or a tail. The probability of obtaining a tail when a coin is tossed is $\frac{1}{2}$, i.e. $0.5$.

$\therefore$ Option (b.) is the correct answer.