Peter and John played in fifteen rounds game. In each round, the winner scored 5 points and the loser scored 2 points. At the end of the game, John’s total score was 57 points. How many rounds did Peter win?
There are 15 rounds with 5 + 2 points available for scoring or a total of 15 (5 +2) = 105 points
Peter must have won 105 - (John's points) = 105-57= 48 points
(15 - w)2 + w(5) = 48 Where 'w' is the number of Peter's wins
30 - 2w + 5w = 48
30 +3w = 48
3w = 18
w =6 Peter won 6 times for 30 points and lost 9 times for 18 points for 48 total points
