This is a standard multinomial coefficient application.

Number the marbles 1, 2, … 10 and then count the ways of putting them into three bins: red bin size 2, white bin size 3, blue bin size 5.

In other words, for the three bins: r1=2, r2=3, and r3=5.

(nr1,r2,r3)(102,3,5)10!2!3!5!2520