Express 1 cm3 in m3 please help ​

What is the greater volume 72 quarts or 23 gallons

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?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.