Question:
A number is selected from first 50 natural numbers. What is the probability that it is a multiple of 3 or 5?
(a) $\frac{13}{25}$
(b) $\frac{21}{50}$
(c) $\frac{12}{25}$
(d) $\frac{23}{50}$
Solution:
GIVEN: A number is selected from 50 natural numbers
TO FIND: Probability that the number selected is a multiple of 3 or 5
Total number is 50
Total numbers which are multiple of 3 or 5 up to 50 natural numbers are
3,6,5,9,10,12,15,18,20,21,24,25,27,30,33,35,36,39,40,42,45,48,50
Total number which are multiple of 3 or 5 up to 50 natural numbers are23
We know that PROBABILITY = 
Hence probability that the number selected is a multiple of 3 or 5 is equal to
The correct answer is option 