How many two-digit numbers are divisible by 3 or 5?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 42
The smallest two-digit number divisible by 3 is 12 and the largest is 99
Thus, there are 30 two-digit numbers divisible by 3
The smallest two-digit number divisible by 5 is 15 and the largest is 95
Thus, there are 18 two-digit numbers divisible by 5
There are a few numbers that are divisible by both 3 and 5, we have counted them twice above. Thus, we have to subtract such numbers. These numbers are simply the multiple of LCM of 3 and 5
Lcm of 3 and 5 = 15
Thus, 15 , 30 , 45 , 60 , 75 , 90
Thus, the required number of numbers = 30 + 18 - 6 = 42