If Jamal has 2 times as many quarters as dimes and they have a combined value of 420 cents, how many of each coin does he have

1. There are 648 total combinations that can be chosen.

2. After she choses two possiblilities the total number changes to 108 total posibilities to chose from

Step-by-step explanation:

possibility: 1/2 x 1/3 x 1/2 x 1/6 x 1/9 = 648

then you remove the first two because she chose those ones

1/2 x 1/6 x 1/9 = 108 possibilities left