Answer: An increase in demand, all other things unchanged, will cause the equilibrium price to rise; quantity supplied will increase. A decrease in demand will cause the equilibrium price to fall; quantity supplied will decrease. ... A decrease in supply will cause the equilibrium price to rise; quantity demanded will decrease.
C is the answer to your question
1) they would wash about 11 cars per hour 72/6.5
2) 13.99 per 1/2 pound 34.99/2.5
58 because she is increasing 8 minutes a day