Question

the sum of the integers from 1 to 100 which are divisible by 3 and 5

Answer 1

Answer:

15+30=45

Step-by-step explanation:

15 is both divisible by 3 and 5

30 is also divisible by 3 and 5

Answer 2

Lcm of 3and 5 is 15
15 30 45 60 75 and 90 divisible by both 3and 5
So sum of these = average * total number
Avg of them = (15+90)/2 = 52.5
So ans is 52.5* 6 = 315