PLEASE HELP 1) A business rents cars for $120 a day and vans for $250 a day. One day it rented a total of 21 vehicles and made $3300. How many cars and vans were rented?

2) A business rents cars for $120 a day and vans for $250 a day. One day it rented a total of 21 vehicles and made $3300. How many cars and vans were rented?

3)Flying against the wind, a plane travels 2800 km in 4 hours. Flying with the wind it travels 4000 km in 5 hours. What is the rate of the plane in still air and what is the rate of the wind?

Using pert, adam munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months, and the project variance is 4. a) what is the probability that the project will be completed in 17 months? b) what is the probability that the project will be completed in 20 months? c) what is the probability that the project will be completed in 23 months? d) what is the probability that the project will be completed in 25 months? e) what is the due date that yields a 95% chance of completion?