If the sum of two consecutive integers is less than 83, how do you find the pair of integers with the greatest sum?

1 Answer
Jun 4, 2015

Two integers can only add to become another integer. The greatest integer less than #83# is #82#.

However, you can't have two consecutive integers adding up to give an even number, so we're going to have to pick the greatest odd number that's smaller than #83#, which is of course #81#.

So we are looking for two consecutive integers that add up to #81#. We are looking for a number #a# and the number after it #a+1#.
To do this, we can add them and set them equal to #83#.

#a + (a+1) = 83#
#2a = 82#

#a = 41#
#(a+ 1) = 42#
#41+42 = 83#

And that is good information, by we are looking for the biggest odd number that's smaller than #83# so we can subtract #1# from both numbers.

#(a-1) = 40#
#a = 41#
#40+41 = 81#