Question

A two digit number is to be formed from the digits 0, 1, 2, 3, 4. Repetition of the digits is allowed. Find the probability that the number so formed is a - prime number.

Answer 1

Two digits numbers which can be formed using the digits 0, 1, 2, 3, 4 are 10, 11, 12 ,13 ,14 ,20, 21 ,22, 23, 24, 30, 31, 32, 33, 34, 40, 41, 42, 43 and 44
Therefore, total numbers outcomes = 20

Number of favourable outcomes (prime numbers) = 11, 13, 23, 31, 41 and 43
= 6
Therefore, required probability =`\text { Number of favorable outcomes}/text { Total number of outcomes}`

`=6/20`

`=3/10`

Hence, the probability that the prime number formed is `=3/10`