x, y and z are three positive numbers such that y is $$\frac{4}{5}$$ times of x and z is $$\frac{5}{8}$$ times of y. If the average of reciprocals of the numbers x, y and z is $$\frac{17}{240}$$, then the average of 3 times of x and 5 times of y will be:

A

70

B

60

C

40

D

45