Bunuel wrote:

If A, B, C, and D are positive numbers such that the ratio of A to B is 3 to 4, the ratio of B to D is 8 to 5, and the ratio of C to D is 3 to 2, what is the ratio of A to C?

(A) 4 to 5

(B) 5 to 4

(C) 5 to 9

(D) 9 to 5

(E) 16 to 5

We'll expand the ratios to a common multiple to solve the question.

This is a Precise approach.

We'll first write things out clearly:

A:B = 3:4

B:D = 8:5

C:D = 3:2

We can comapre A:B to B:D by multiplying A:B by 2 --> A:B:D = 6:8:5

We can next compare B:D to C:D by multiplying C:D by 2.5 --> C:D = 7.5:5 so B:C:D = 8: 7.5 : 5

Then A:C = 6 : 7.5 = 12:15 = 4:5

(A) is our answer.

_________________

David

Senior tutor at examPAL

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