Question

find sum 5+10+15+20+25+........+100​

Answer 1

Answer:

1155

Step-by-step explanation:

Just add them.

Or, you can pair them up:

(5 + 100) + (10 + 95), etc.

    105           105

And, you find how many pairs there are:

In this case, there are 11 pairs of numbers that add up to 105, so you multiply:

11 * 105 = 1155