Help me with this please

Suppose your school costs for this term were $4900 and financial aid covered 3/4 of that amount. how much did financial aid cover? and how much do you still have to pay?

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

The water company charges a residential customer $41 for the first 3,000 gallons of water used and $1 for every 200 gallons used over 3000 gallons. if the water bill was $58 how many gallons of water were usedanswersa 3400 gallonsb 6000 gallonsc 6400 gallons d 7000 gallons