Start from 110 feet away, a person on a bicycle rides towards a checkpoint and then passes it. the rider is travelling at a constant rate of 30 feet per second. the distance between the bicycle and the checkpoint is given by the equation d=|110-30t| at what times is the bike 40 feet away from the checkpoint?
a. 2.3 sec and 5 sec
b. 1.6 sec and 5 sec
c. 2.3 sec and 4.6 sec
d. 1.6 sec and 4.6 sec