Question

Find the sum of first 15 multiples of 8?
​

Answer 1

Answer:

Here's your answer mate

Step-by-step explanation:

Let to be a is the first term and ‘d’ is the common difference and l is the last term of Given Arithmetic Sequence or Progression.

Arithmetic Sequence or Progression;- 8,16,24,32….

Here, the First term = 8

Common Difference = 8

Number of terms = 15

We know that Formula of Summation of Arithmetic Sequence or Progression.

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

S15 = 15/2(2×8+(15-1)8

= 15/2(16+(14)8)

= 15/2(16+112)

= 15/2 x 128

= 15 x 64

= 960

The sum of the first 15 multiples of 8 is 960