(4x^3y)(-2x^4y^-1)^2(6x^8y^5)^0 PL HELP ME

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

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. how many hours after the truck's departure will the two meet?

For the chance to be team captain, the numbers 1-30 are put in a hat and you get two chances to pick a number, without replacement. which formula correctly shows how to find the probability that you choose the number 1 and then 2?