Need help solving this ASAP!

A group of middle school students wants to raise money to help build a new school track. They decided to sell donuts before school. Demand is 250 donuts when the donuts are given away free, and the demand drops to 150 donuts when the price is 25 cents per donut. However, the middle school adminstration is prepared to supply only 100 donuts free of charge but will supply 150 donuts when the price is 50 cents per donut. Assume that the demand and supply functions are both linear functions. What price should the students charge per donut so that there is neither a surplus nor a shortage of donuts? a) 30 cents per donut . ob) 35 cents per donut. c) 25 cents per donut. d) 45 cents per donut