Question

the sum of first fifteen multiple of 8 is
​

Answer 1

Answer:

15*8=

Step-by-step explanation:

Answer 2

Step-by-step explanation:

8 , 16 , 24 , ....... , 120

they are in A.P common difference is 8

sum of first n terms of A.P = n(2a+(n-1)d)/2

a + (n-1)d = 120

8 + (n-1)8 = 120

(n-1) = 112/8

n-1 = 14

n = 15

now sum of first fifteen multiples of 8

= 15(2×8 + (15 - 1) 8) / 2

= 15(128) / 2

= 15(64)

= 960

i hope this is correct