The number of apps a developer sells daily has the probability distribution represented in the table. Number of Apps, x | 0 20 40 60 80 100
P(x) 0.05 0.25 | 0.18 0.12 0.3 0.1

If each app sells for $5.99, what is the expected daily total dollar amount taken in by the developer from the sale of apps?
A. $5.99
B. $53.40
C. $59.90
D. $314.22
E. $319.87

Divide the following fractions 3/4 ÷ 2/3 1/2 8/9 9/8 2

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?

Me because i don't understand how to do it.: )