Skip to main content
OlympiadHQ

Browse · MATH

Print

jmc

algebra junior

Problem

What is the sum of the odd integers between 46 and 64?
Solution
The odd integers between 46 and 64 are 47, 49, , 63. These integers form an arithmetic sequence with common difference 2, so the term in this sequence is .

If , then , so there are 9 such odd integers. The sum of an arithmetic series is equal to the average of the first and last term, multiplied by the number of terms, so the sum is .
Final answer
495