A triangular pyramid has a base shaped like an equilateral triangle. The legs of the equilateral triangle are all 7 centimeters long, and the height of the equilateral triangle is 6.1 centimeters. The pyramid's slant height is 11 centimeters. What is its surface area?

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?