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Source: — Data Sufficiency |

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by Matt@VeritasPrep » Sun Oct 12, 2014 9:31 pm
The key insight here is that r and n are the same for each person, so the ONLY variable that matters in the ratio is P: r and n will cancel in both the numerator and the denominator. Here's a visual:

Image

So we only need to know A in terms of B, and we're done. S1 tells us A/B = 1/4; SUFFICIENT. S2 tells us the same thing; SUFFICIENT.