Lesson: Eliminating Fractions

Comment on Eliminating Fractions

How do we find the least common multiple of all 5 denominators? (which = (5^5)(7^5)) for this question:

https://gmatclub.com/forum/which-of-the-following-has-the-greatest-value-248206.html
gmat-admin's picture

Question link: https://gmatclub.com/forum/which-of-the-following-has-the-greatest-value...

I knew that the least common multiple of the five denominators will consist of powers of 5 and 7.

First, since the biggest power of 5 is 5^5, the least common multiple must have 5^5

Likewise, since the biggest power of 7 is 7^5, the least common multiple must have 7^5.

Does that help?

Cheers,
Brent

It was nice to see this different question! :)

for the first one you can just multiply 5 to both side, though it can be larger number to solve.
gmat-admin's picture

That also works.

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