A kayak can travel 80 miles downstream in 10 hours while it

A kayak can travel 80 miles downstream in 10 hours, while it would take 40 hours to make me same trip upstream. Find the speed of the kayak in still water, as well as the speed of the current. What is the speed of the kayak? mph

Solution

downstream

d = 80 miles

t = 10 hr

v= d/t = 80/10 = 8 mph

upstream

t = 40 hr

v = 80/40 = 2mph

So for upside

Vk - Vc = 2

for downside

Vk + Vc = 8

solving both equation

Vk = 5 mph = speed of kayak

Vc = 3 mph = speed of current