A bank manager wants to encourage new customers to open accounts with principals of at least 3000 $. He decides to make a poster advertising a simple interest rate of 3 %. What must the principal be if the bank manager also wants to advertise that one can earn $ 10 tthefirst month? Can the poster correctly say, "Open an account of $ 3000 and earn at least $ 10 interest in 1 month!"?

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?