1. there are 18 peices of music to choose from 6 for piano, 5 for violin and 7 for guitar. in how many ways can you choose 3 peices of music if at least 1 must be for piano.
2. you are thinking of using some left over ceramic tiles to make a decorative border for a patio. you have 10 blue, 4 gold and 6 white tiles. in how many ways can you place the tiles to make the border if you need 12 tiles and you use all three colours with at least 8 blue tiles and more gold tiles than white tiles?

(please explain the soloution step by step as im a bit confused on the topic and would like to gain an understanding)