Browse · MATH
Printjmc
algebra senior
Problem
The average of two 2-digit positive integers is equal to the decimal number obtained by writing one of the two-digit integers before the decimal point and the other two-digit integer after the decimal point. What is the smaller of the two integers?
Solution
Let the two numbers be and (where and are digits). The average of and is and the number formed by writing before the decimal point and after the decimal point is: Setting these equal gives: From this it follows that a multiple of 50. As is a 2-digit positive integer this means that . So now , so . Thus the integers are and , so the smaller integer is .
Final answer
49