An insurance sales representative selects 4 policies to review. The group of policies she can select from contains 10 life policies, 5 automobile policies, and 3 homeowners policies. Find the probability of selecting all life policies.

Question

An insurance sales representative selects 4 policies to review.  The group of policies she can select from contains 10 life policies, 5 automobile policies, and 3 homeowners policies.  Find the probability of selecting all life policies.

The number of ways to select all life insurance policies is 10C4.  Hence, 
P)all life policies = 10C4 = 210 = 7 
                                  -------------
                                 18C4 =3060    102
Can someone tell me how did you get the 210 and the 3060.  I need it broke down step by step then I can follow it.

Thanks for your help.  This is for my final.