Question

12. Find the sum of
(i) the first 15 multiples of 8

(ii) the first 40 positive integers divisible by (a) 3 (b)5(c)6.

all 3 - digit natural numbers which are divisible by 13.

all 3-digit natural numbers, which are multiples of 11.

f) all 2-digit natural numbers divisible by 4

(vi) first 8 multiples of 3.
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Answer 1

Answer:

(i) Sn= n/2(2a+(n-1)d)

here n=15 a=8and d=8

the 15/2*(16+14*8)

15/2*128

15*64= 960

Answer 2

Answer:

hello I am Saurabh I am giving your answer don't worry about it the answer is (1)916