Find the probability that a number selected at random from the numbers 1, 2, 3, ..., 35 is a
(i) prime number
(ii) multiple of 7
(iii) a multiple of 3 or 5
GIVEN: A number is selected from numbers 1 to 35
TO FIND: Probability of getting a number
(i) which is a prime number
(ii) multiple of 7
(iii) multiple of 3 or 5
Total number of cards is 35
(i) Numbers that are primes are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 and 31
Total prime numbers from 1 to 35 are11
We know that PROBABILITY = 
Hence probability of getting a number which is a prime from 1 to 35 is equal to 
(ii) Numbers that are multiple of 7 are 7,14,21,28,35
Total number that are multiple of 7 from 1 to 35 are5
We know that PROBABILITY =
Hence probability of getting number that is multiple of 7 from 1 to 35 is 
(iii) Numbers that are multiple of 3 and 5 are 3, 5, 6, 8, 10, 12, 15, 18, 20, 21, 24, 25, 27, 30, 33 and 35
Total numbers that are multiple of 3 or 5 from 1 to 35 is 16
We know that PROBABILITY =
Hence probability of getting number that is multiple of 3 or 5 from 1 to 35 is equal to 