Question

A boat goes 15 mph in still​ water, and the rate of the current is t mph.

Answer 1

Answer:

a) 15-t mph;

b) 15+t mph.

Step-by-step explanation:

a) When the boat travels​ upstream, the current hinders the boat (the speed of the boat decreases). Thus, the speed of the boat upstream becomes

15-t mph.

b) When the boat travels​ downstream, the current helps the boat (the speed of the boat increases). Thus, the speed of the boat downstream becomes

15+t mph.