Sarafina and Katie have between $105 and $420 dollars to spend on jewelry for Christmas presents for their friends. If they buy 7 bracelets at $3.25 each and 8 necklaces at $11.75 each, how many pairs of earrings can they buy if they cost $6.15 each? Set up the compound inequality and solve. YOU MUST SHOW YOUR STEPS TO RECEIVE FULL CREDIT.

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?