Can someone fill out i am horribly at this in adavance

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults.how many students and adults went if the ticket charge was $42.75

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount