A motorboat takes 5 hours to travel 200mi going upstream. The return trip takes 4 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?

Question

A motorboat takes 5

 hours to travel 200mi

 going upstream. The return trip takes 4

 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?

Rate of the boat in still water:

Rate of the current:

Answer 1

X= Rate in still water

c = Rate in current water

x+ c = Rate in downstream

x-c = Rate in upstream

time * Rate= Distance

5(x+c)= 200

4(x-c)=200

5x+ 5c =200 multiply by 4 = 20x+20c = 800

4x-4c= 200 multiply by 5= 20x-20c = 1000

solve system of equation

40x= 1800

x= 45

4*45-4c=200

c= 5