Question

. Find the sum of first 8 multiplies of 3.​

Answer 1

Answer:

The sum of the first 8 multiples of 3 is 108.27

Answer 2

Answer:

First 8 multiples of 3-

• 3,6,9,_________upto 8 terms

The above series is in A.P. where,

• First term (a)=3
• Common difference (d)=3
• No. of terms (n)=8
• Sum of terms (Sn)=?

As we know that, in an A.P.,

$\sf S_n= \frac{n}{2} [2a+(n−1)d]$

$\sf ∴S_8 = \cancel \frac{8}{2} [2×3+(8−1)×3]$

$\sf \implies S_8=4×(6+21)$

$\sf \implies S_8 =4×27$

$\sf \implies S_8 =108$

The sum of first 8 multiplies of 3 is 108.