Find the sum of the first 15 multiples of 8

Answer:

Exploring the multiples of 8. At this moment, they are 8,16,24,32, 40, and so on.

All these are formed in A.P., denoting the number 8, which is referred to as the first term. Currently focusing on the common factor difference, says 8.

Hence a=8, d=8,

So, S15 =?

Using the formula, Sn=n/2 [2a+(n-1) d]

Now putting the values in the formula, S15= 15/2 [2(8) + (15-1)8]

On solving, we get 15/2 [16+ (14) (8)]

Further solving, we get 15 * 128 divided by 2

The answer to this question would be: 960 

The exact answer to this:

As explained, the sum of the first 15 multiples of 8 will be 960.

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