Math CentralQuandaries & Queries


Question from gowtham, a student:

The sum of two consecutive odd integers is 20. find the integers

Hi Gowtham,

The subject line of your email was "algebra" so I think you are expected to use algebra to solve this problem so I will suggest a technique using algebra. I my mind this is the wrong way to solve this problem. I will show you a way that doesn't use algebra and one you can do in your head.


Suppose the smaller of the two integers is $n.$ The next integer is $n + 1$ but that's even so the next odd integer is $n + 2.$ Set the sum of these two integers to 20 and solve for $n.$

No algebra:

The two integer being sought are very close. If they were the same integer with a sum of 20 then they would both be 10. What two odd integers, close to 10, have a sum of 20?


About Math Central


Math Central is supported by the University of Regina and the Imperial Oil Foundation.
Quandaries & Queries page Home page University of Regina