Question

Find the indicated sum.

∑5i=1(i+11)


A. 16

B. 70

C. 54

D. 28

Answer 1

B. 70

Explanation:

We have the sum given by
`\sum_(i=1)^(5)(i+11)).`

Now, we open the summation by substituting the values of 'i',

i.e.
`\sum_(i=1)^(5)(i+11)).` = (1+11) + (2+11) + (3+11) +(4+11) +(5+11)

i.e.
`\sum_(i=1)^(5)(i+11)).` = 12 + 13 + 14 + 15 + 16

i.e.
`\sum_(i=1)^(5)(i+11)).` = 70.

Hence, the sum of
`\sum_(i=1)^(5)(i+11)).` is 70.

So, option B is correct.