Question #dd09d

1 Answer
Jun 21, 2017

875

Explanation:

The sum of the first #n# odd numbers is equal to #n^2#.

In order to find the sum of the odd numbers between #10# and #60#, just find the sum of the odd numbers below #60# and subtract the sum of the odd numbers below #10#.

Since there are #30# odd numbers below #60# (the sum of these odd numbers would be #30^2#) and #5# odd numbers below #10# (the sum of these odd numbers would be #5^2#), the answer is #30^2-5^2=900-25=875#.