Question

Cards bearing numbers $2,4,6,8,10,12,14,16,18$ and $20$ are kept in a bag. A card is drawn at random from the bag. Find the probability of getting a card which is?

(A) A prime number.

(B) A number is divisible by $4$.

(C) A number that is a multiple of $6$.

(D) An odd number.

Answer 1

There are a total of $10$ cards in the bag, all bearing even numbers on them.

A. Since the only even prime number is $2$ and there is exactly one card which bears this number, the probability of drawing a card with a prime number on it is $\frac{1}{10}=0.1$

B. There are $5$ numbers divisible by $4,$ they are $4,8,12,16,20.$ So, the probability of drawing a card which has a number divisible by $4$ on it is $\frac{5}{10}=0.5$

C. There are $3$ numbers which are multiples of $6$, they are $6,12,18.$ So, the probability of drawing a card which has a number divisible by $6$ on it is $\frac{3}{10}=0.3$

D. There is no odd-numbered card in the bag. So the probability of drawing a card with an odd number on it is $0$.