Abasketball team played 15 games and won 80% of them. if the team expects to play 30 games in all, how many more games must it win to finish the season with a 90% winning percentage?

So 80% of 15 games won equal 12 games won and 3 lost. This is because 15/10 = 1.5 and 1.5 x 8 =12.
For 30, you do the exact same thing but with 90% instead. 30/10 = 3. 3 x 9 = 27.
So they need to have won 27 games to get a 90% winning percentage out of 30 games.
But since the question asks how many MORE games they need to play, it'll be 27-12 = 15.
So they need to win 15 more games to get a 90% winning percentage