2/3 + 1/4 -3. What is the anwser

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?

Rob filled 5 fewer plastic boxes with football cards than basketball cards. he filled 11 boxes with basketball cards.

The mass of a marine organism, in pounds, p years after it is born is given by the polynomial function r(p) = -4p2 + 300p. find the mass when p = 20 years.