AMC 10 2008a Problem 12

In a collection of red, blue, and green marbles, there are $25\%$ more red marbles than blue marbles, and there are $60\%$ more green marbles than red marbles. Suppose that there are $r$ red marbles. What is the total number of marbles in the collection? $\mathrm{(A)}\ 2.85r \mathrm{(B)}\ 3r \mathrm{(C)}\ 3.4r \mathrm{(D)}\ 3.85r \mathrm{(E)}\ 4.25r$