[JMO 2012 A8] An athletics club has junior (i. e. boy or girl) members and
adult members. The ratio of girls to
boys to adults is 3:4:9 and there
are 16 more adult members than
junior members. In total, how many
members does the club have?

The students at jefferson middle school are raising money for a charity by selling t-shirts and hats. the number of t-shirts sold was 3 times the number of hats. the profit was $5 for each t-shirt sold and $2.50 for each hat sold. the students raised $840 for the charity. they used the system below to analyze their success and found the solution to be (144, 48). 5x+2.50y=840 x=3y how much did they earn from t-shirt sales?