Jill has a fish tank with danios and catfish. She has a total of 22 fish in the fish tank. There are more catfish than danios. The catfish are two more than three times the danios. How many catfish and danios does Jill have in the fish tank? What pair of variables will best reflect the catfish and danios?
Question 1 options:

10 and 11

3 and 4

c and d

squares and circles

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?