The dail on a 3 number combination lock contains markings to represent the numbers 0-59. How many combination's are possible in each case?

a. the first and second numbers must be different, and the second and third numbers must be different.

b. the first and second numbers must differ by atleast 3.

I dont know how to do these.

is it.... $\displaystyle 3^{60}=4.24*10^{28}$ divided by something.........????