Math beast problem

[Christyida]

Hey
I had a small doubt regarding last Week's Problem: "At Least"

If 3|90x and 2|y/75 are positive integers, what is the least possible value of xy?

Since the question specifies that cube root of 90x and the square root of y/75 are integers,can we substitute x as 1/90 (reciprocal of 90) and y as 75.thus the product will be 75/90.

awaiting a quick response
Christy

[kwame.appau]

I side with you christy, since there were not any constraint that 90x is not equal to 1. I am confused as I saw the solution this morning. I got 75/90, equivalent to 0.8333. I think we need justification on the answer. thanks.

[tommywallach]

Hey Guys,

I totally agree with you both. Clearly, the original question should have stated that x and y both have to be positive integers themselves. I'll make sure to update the question for future students. Great catch!

-t