If 60 percent of a rectangular floor

Vincen wrote:If 60 percent of a rectangular floor is covered by a rectangular rug that is 9 feet by 12 feet, what is the area, in square feet, of the floor?

(A) 65
(B) 108
(C) 180
(D) 270
(E) 300

Area of rectangular RUG = (base)(height) = (9)(12) =108
This RUG covers 60% of the FLOOR
In other words, 108 = 60% of the area of the FLOOR
Or we can write: 108 = 0.6(area of FLOOR)

So, 108 /0.6 = area of FLOOR
Evaluate to get: 180 = area of FLOOR

Answer: C

Cheers,
Brent

Vincen wrote:If 60 percent of a rectangular floor is covered by a rectangular rug that is 9 feet by 12 feet, what is the area, in square feet, of the floor?

(A) 65
(B) 108
(C) 180
(D) 270
(E) 300

PRO TIP
Once we know that So, 108 /0.6 = area of FLOOR, we can apply some number sense to avoid dividing 0.6 into 108

Notice that 108 /0.5 = 216
Since 0.6 is a bit bigger than 0.5, we know that 108 /0.6 will be a little bit less than 216
Check the answer choices...only answer choice C is a bit less than 216

ASIDE: This shortcut works, because the answer choices are nicely spread apart.

For more on this strategy, watch our math tips video: https://www.youtube.com/watch?v=8GqcJGUVIk4

Cheers,
Brent

Hi Vincen,

With this question, we can use the answer choices 'against' the prompt and TEST THE ANSWERS. To start, we know that the area of the rug is...

(9 ft)(12 ft) = 108 ft^2

We're told that this value represents 60% of the area of the rug. Since we're asked to find the area of the rug, 108 is 60% of one of the answer choices.

Since 60% of 200 = 120, we're clearly looking for an answer that is LESS than200 (but not that much less).

Let's TEST Answer C: 180

(.6)(180) = 108

This is an exact match for what we were told, so this must be the answer.

Final Answer: C

GMAT assassins aren't born, they're made,
Rich