linear equations with two variables word problem

Question

A motorboat traveling with the current went 35 mi in 3.5 hr. Traveling against the current , the boat went 12 mi in 3 hr. Find the rate of the boat in calm water and the rate of the current.

Answer 1

boat speed with current = 35/3.5 =10 mph

boat speed against current = 12/3 = 4 mph

Midpoint is the boat's speed= (10+4)/2 = 7 mph

Difference is the current's speed = 10-7 = 3 mph.