We can interpret the ratios as \(A = \frac{2}{3}B = \frac{3}{4}S \)(where A = the number of stamps Andy's collected, B = the number of stamps that Brian collected, and S = the number of stamps that Suzy collected).

It makes sense to plug in an integer for A, and the easiest would be 12 because that's the Lowest Common Denominator of the ratios. That makes B = 18, and S = 16, and the total number of stamps collected = 46.

There would only be 3 calculations necessary for the differences between any 2 of the 3:
S - A = 4
B - S = 2
B - A = 6

Then divide each difference by 46:
\(\frac{4 }{ 46} = 8.70\)%, \(\frac{2}{46} = 4.35\)%, and \(\frac{6}{46} = 13.0\)%