Find the sum of all natural no. between 101 & 304 which are divisible by 3 or 5.
Find their sum.
Ans: No let 101 and 304, which are divisible by 3.
102, 105.............303 (68 terms)
No. which are divisible by 5 are 105, 110......300 (40 terms)
No. which are divisible by 15 (3 & 5) 105, 120...... (14 terms)
∴ There are 94 terms between 101 & 304 divisible by 3 or 5. (68 + 40 - 14)
∴ S68 + S40 - S14
= 19035