The times for the race came down with practice. The average time for the 5 racers in the first race was 57 seconds. The average time for the second race was 55 seconds. For the third race, the average time was 52 seconds. What was the average time for all three races?

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?