Question

find the sum of first 15th multiple of 8.

Answer 1

Answer:

HERE,

a=8

n=15

d=8

Sn = n/2 [2a + (n - 1)d]        

,substitute the values in the formula

S15 = 15/2 [2(8) + (15 - 1)8]

= 15/2[6 + (14) (8)]

= 15/2[16 + 112]

= 15(128)/2

= 15 × 64

= 960

Answer 2

the ans of your question is 960.hope it helps you and mark me as brainliest.