At a sale, shirts were sold for 15 each . this price was 80%of thier original price . what was the origial price

Andrea went to the store to buy sweater that was on sale for 40% off the original price it was then put on clearance an additional 25% off the sale price she also use a coupon that saved her an additional five dollars and j did not spend more than $7.60 for the sweater what are the possible values for the original price of the sweater?

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.