You want to purchase a new car in 3 years and you anticipate the cost of the car to be $25,000. You are given an investment plan with a fixed APR of 5.3% if you make regular monthly deposits. How much should you deposit at the end of each month to reach your goal of $25,000 in 3 years?

a.$642.23

c.$648.62

b.$645.65

d.$649.13

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?