Sequence And Series Question 394
Question: The sum of all natural numbers between 1 and 100 which are multiples of 3 is
[MP PET 1984]
Options:
A) 1680
B) 1683
C) 1681
D) 1682
Show Answer
Answer:
Correct Answer: B
Solution:
We get series 3, 6, 9, 12,…….. 99. Here $ n=\frac{99}{3}=33,\ a=3,\ d=3 $ , therefore $ S=\frac{33}{2}{ 2\times 3+(33-1)3 } $ $ =\frac{33}{2}\times 102=33\times 51=1683 $ .
BETA
