Question

What is the number of integers between 200 and 500 that are divisible by 12 or 15 but not by 30? ​

Answer 1

Any number divisible by both 12 and 15 will always be divisible by 30

Divisble by 12= 500/12 -200/12 =25 (quotient only)

Divisble by 15= 500/15 -200/15 =20 (quotient only)

Divisble by 30= 500/30 -200/30 =10 (quotient only)

Divisble by 60= 500/60 -200/60 =5 (quotient only)

Divisible by 12 and 15 i.e, divisible by 60 which is divisible by 30= 5

Number of integers between 200 and 500 that are divisible by 12 or 15 but not 30=(25–5)+(20–5)-(10–5)=30