Agrocery store bought milk for $2.70 per half gallon and stored it in two refrigerators. during the night, one refrigerator malfunctioned and ruined 12 half gallons. if the remaining milk is sold for $4.02 per half gallon, how many half gallons did the store buy if they made a profit of $60.00?

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?