BTGmoderatorLU wrote: ↑

Tue Mar 10, 2020 12:28 pm

Source: Manhattan Prep

Ramon wants to cut a rectangular board into identical square pieces. If the board is 18 inches by 30 inches, what is the least number of square pieces he can cut without wasting any of the board?

A. 4
B. 6
C. 9
D. 12
E. 15

The OA is E

Since we want the least no. of identical squares, the side of each square must be equal to HCF of 18 and 30.

HCF of 18 and 30 = 6.

Least no. of identical squares = 18/6 * 30/6 = 3*5 = 15

The correct answer: E

Hope this helps!

-Jay
_________________
Manhattan Review

Locations: Manhattan Review Himayatnagar | GMAT Prep Hyderabad | GRE Prep Bangalore | Chennai GRE Coaching | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

BTGmoderatorLU wrote: ↑

Tue Mar 10, 2020 12:28 pm

Source: Manhattan Prep

Ramon wants to cut a rectangular board into identical square pieces. If the board is 18 inches by 30 inches, what is the least number of square pieces he can cut without wasting any of the board?

A. 4
B. 6
C. 9
D. 12
E. 15

The OA is E

If we aren't wasting any wood, the length and width must be divisible by one side of the square
So, this question is a clever way of asking us what the greatest common divisor (GCD) of 18 and 30
The GCD of 18 and 30 is 6, so if we cut squares that are 6 x 6, then we won't waste any wood.

We get something like this:


So, we can cut 15 squares.
Answer: E

Cheers,
Brent