A toy rocket launched into the air has a height (h feet) at any given time (t seconds) as h=- 16t^2 + 160t until it hits the ground. At what time(s)is it at a height of 9 feet above the ground?

The u-drive rent-a-truck company plans to spend $13 million on 320 new vehicles. each commercial van will cost $25 comma 000, each small truck $50 comma 000, and each large truck  $80 comma 000. past experience shows that they need twice as many vans as small trucks. how many of each type of vehicle can they buy?

If a is a nonzero real number then the reciprocal of a is

Many newspapers carry a certain puzzle in which the reader must unscramble letters to form words. how many ways can the letters of emdangl be arranged? identify the correct unscrambling, then determine the probability of getting that result by randomly selecting one arrangement of the given letters.