Help me I need to get this right

In a sale there is 25% of all prices a chair costs £45 in sale how much was it before the sale

Whats the theoretical probability of popping a polka dot balloon? express your answer as a fraction, decimal and percent solid 15 polka dot 5 striped 17 plzz me due tomorrow

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?