Verify mobile number to view the solution
Solutions
There are a total of 25 prime numbers below hundred.
Based on this the original probability of picking a prime numbered ball must be 25/100 = 1/4.
But since Ramesh misreads this to 140 he calculates this for 140.
Between 100 and 140 the additional prime numbers are 101, 103, 107, 109, 113, 127, 131, 137, 139.
Hence the probability that Ramesh calculates is 34/140.
The original probability is 1/4 = 35/140.
The probability calculated by Ramesh = 34/140.
The difference between the two probabilities = 35/140 - 34/140 = 1/140
Hence, Option C is the correct choice.