A kayaker paddles upstream from camp to photograph a waterfall and returns. The kayaker's speed while traveling upstream and downstream is shown below. What is the kayaker's speed in still water? What is the speed of the current?

Let's denote the speed of the kayaker in still water as S and the speed of the current as C.

Speed upstream = S - C
Speed downstream = S + C

From the given information:
Speed upstream = 2 mph
Speed downstream = 4 mph

We can set up the following equations:
S - C = 2
S + C = 4

Adding the two equations together, we get:
2S = 6
S = 3 mph

Substitute S = 3 into one of the equations to solve for C:
3 - C = 2
C = 1 mph

Therefore, the kayaker's speed in still water is 3 mph and the speed of the current is 1 mph.