Bunuel wrote:

A carpet is y yards long and f feet wide. How many dollars will it cost if the carpet sells for x cents per square foot? (1 yard = 3 feet)

(A) xyf

(B) 3xyf

(C) xyf/3

(D) 0.03yf/x

(E) 0.03xyf

IMO E.

This is a conversion problem and the conversion factor is given - 1 yard is equal to 3 feet.

length of carpet = y yards = 3y feet.

width = f feet.

area = length * wight = 3yf square feet.

rate of carpet = x cents per square feet.

cost ( in cents ) = 3xyf

this is the trap option! We are asked cost in dollars not cents... so we need to apply the implicit conversion of 100 cents a dollarcost ( in dollars ) = 3xyf / 100 or 0.03xyf.

Hence Option E.

Best,

Gladi