Jim has 8 cds that he is going to give away. he lets his best friend choose 2 of the 8 cds. how many different groups of 2 cds are possible?

27

Step-by-step explanation:

1 with 2,3,4,5,6,7,8=7 pairs

2 with 3,4,5,6,7,8=6 pairs

3 with 4,5,6,7,8=5 pairs

4 with 5,6,7,8=4 pairs

5 with 6,7,8=3 pairs

6 with 7,8=2 pairs

7,8=1 pair

Add them to get 27

1. is 4 and 2. is 3

step-by-step explanation:

so if you look at the first one you see that 1 is to 4 and 2 is to 8 and so on, so you can see for every 1 there is a times 4 so if it were 3 then it would be 3*4 and it is 12

for number 2 it is 3 because 1 is to 3 and 2 is to 6 so for every 1 there is 3 so if it were 3 then there would be 3*3 = 9