Chuanxi planned a rectangular sidewalk with a length of 21 ft. He made a scale drawing using a scale factor of 1 in. = 7 ft. He decided to change the length of the actual sidewalk to 27 ft. If the scale drawing still has a length of 3 in., what does 1 in. represent in the new scale?
Accepted Solution
A:
Original Ratio of 1 in = 7 ft so 3 in = 21 ft Now, New ratio 1 in = x ft so 3 in = 27ft
1/x = 3/27
cross multiply a/b = c/d ad = bc 1/x = 3/27 3x = 27 x = 9