Question

There are 10 marbles in a box with numbers 1 to 10 marked on them. What is the probability that a marble drawn randomly has a prime no. on it

Answer 1

Total outcomes = 1,2,3,4,5,6,7,8,9 and 10

Favourable outcomes = 2,3,5 and 7(Prime no.s from 1 to 10)

Probability of getting a prime number marble =
No. of favourable outcomes
____________________

No. of total outcomes


= 4/10 = 2/5

Answer 2

Given:

Number of marbles in a box = 10

All the marbles are marked with numbers 1 to 10.

To Find:

The probability of getting a prime number on the marble if we draw a marble randomly from the box.

Solution:

Since, Total numbers of marbles in the box = 10

So, Total number of possible outcomes = 10

Also, Prime numbers from 1 to 10 = 2, 3, 5 and 7.

So, Total number of favourable outcomes = 4

Therefore, Probability of drawing a marble with prime number on it

                                                           $= \dfrac{Total \ number \ of \ possible \ outcomes}{Number \ of \ favourable \ outcomes}$

                                                           $= \dfrac{4}{10} = \dfrac{2}{5}$

Thus, Probability of getting a marble with prime number on it = 2/5.