An air traffic controller is monitoring the altitudes of four planes. The four equations below show y, the distance in feet of each plane above the ground, after t minutes of descent. Plane A: Y= -400t+ 12,000
Plane B: y= -800t+ 28,000
Plane C: y= -200t+ 13,500
Plane D: y== -500t + 30,000

Compare the subtraction problems 6/8 - 5/8 = 1/8 and 6/9 - 7/9 = 1/9 why is the answer to the first problem positive and the answer to the second problem negative

33% of college students say they use credit cards because of the rewards program. you randomly select 10 college students and ask each to name the reason he or she uses credit cards. find the probability that the number of college students who say they use credit cards because of the rewards program is (a) exactly two, (b) more than two, and (c) between two and five inclusive. if convenient, use technology to find the probabilities.

This is so hard and it’s for a test