Question

Leland wants to paint a portrait for his parents using a photograph of them that is 5 inches wide by 8 inches high. He wants the portrait to be proportional to the photograph and 42 inches high. Which proportion can Leland use to find w, the width he needs to use to make the portrait proportional?

A. 5/8 = W/42
B. 5/W = 42/8
C. 5/W = 13/8
D. 5/8 = 42/W

Is the answer letter B? If not please show me how to figure out the correct answer.

Answer 1

you want the ratio of L : W to remain at 8 : 5

so 42/W = 8/5
8W = 210
W = 210/8 = 26.25

check:
42/26.25 = 1.6 = 8/5

Of course the ratio could have been expressed in more than one way, but whichever way you choose, the cross-product has to end up as 8W = 210

Looking over your choices , I would pick A

notice your choice yields ...
42W = 40
W = 40/42 = .95... , not even 1 inch, so clearly not correcct

Answer 2

Thank you for explaining.