Data Sufficiency

Hi Experts, Can you please help me on this attached problem.

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:



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.