4. A committee of students and teachers is being formed to study the issue of student parking privileges. Fifteen teachers and 18 students have expressed an interest in serving on the committee. There must be at least
1 teacher and at least 2 students on the committee. How many ways can a
five-person committee be chosen?

Which one is the right answer?
-2,295
-198,900
-201,195
-235,041

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?