The stem-and-leaf display below gives the numbers of dinner orders on 21 different nights at a restaurant. Use the display to answer the questions that follow.
Number of dinner orders
3 126
4024789
*500011389
6/2447
Key: 31 means 31 dinner orders.
(a) What was the least number of orders in the 40s?
DO
(b) What was the greatest number of orders overall?
(c) On how many nights was the number of orders in the 30s?

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?