A boat traveled downstream a distance of 80 mi and then came right back. If the speed of the current was 8 mph and the total trip took 5?

Answer: Average speed of boat = 32mph

Step-by-step explanation: Full question: 5 hours 20mins. Find the average speed of the boat

Let average speed of boat be mph

Let time to travel downstream = 80 / (x + 8)

Let time to travel upstream = 80 / (x - 8)

Total time = 51/3 hrs=16/3 hrs

80 / (x + 8) + 80 / (x-8) = 16/3

Multiply both sides with3 (*+8) (x-8)

(X+8) (x-8) = (x+8) (x-8) / 16

15 (2x) = x^2-64

X^2 - 30x - 64 = 0

Factorizing, you get

(x - 32) (x + 2) = > * =32 or x = - 2

x = 32mph