Kaitlin is participating in a 5-day cross country biking challenge. she biked for 55,67,56,and 49 miles on the first four days. how many miles does she need to bike on the last day so that her average (mean) is 55 miles per day?

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?