There are 50 kids altogether in my son’s grade. each year at his school, the 50 students are divided into two classes of 25 students each (class a and b). for four years in a row, my kid has not been with his best friend. he thinks they’re doing this on purpose. based on probability, what do you think? do you think this is a random assignment, or not?

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?