Question 1096479
4 rap videos can be selected in 10C4 = {{{10!/(6!*4!)}}} ways

3 R&B videos can be selected in 5C3 = {{{5!/(2!*3!)}}} ways

Selected videos can be arranged in 7! ways

Therefore, number of arrangements = {{{10!/(6!*4!) * 5!/(2!*3!) * 7! = 50400}}}