Question

Find the value of 11 +22+33 + ... + 1100.

Answer 1

Answer:

sum of terms: 55550

Explanation:

$\sf S_n = \dfrac{n}{2} (u_{start}+u_{end}})$

Here the number of terms:

1100 ÷ 11 = 100

Using the Formula:

$\sf \dfrac{100}{2} (11+1100)$

$\sf 55550$