If you can complete 4 problems on a test in 9 minutes, how many problems can you finish in 10 minutes

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?

Simplify 24÷(-2)(3)+7 a. -29 b. 3 c. 11

How can i differentiate this equation?