The sum of two numbers is 41. One number is 1 less than the other.

s must be 21 and r is 20

Step-by-step explanation:

Represent the two numbers using variables r and s.

Then r + s = 41, and r = s - 1

Substituting the 2nd equation for r into the first equation, we get:

s - 1 + s = 41, or 2s = 42. Then s must be 21 and r is 20.