What is the rate of the boat in still water and what is the rate of the current?

Question

A motorboat travels 156 kilometers in 6 hours going upstream. It travels 276 kilometers going downstream in the same amount of time. What is the rate of the boat in still water and what is the rate of the current?

Answer 1

156 = 6(b-c)= 6b-6c

276 =6(b+c) = 6b+6c

12b = 156+276= 432

b = 432/12 = 36 km/hr = boat speed in still water

6c =6b-156

c = (6(36)-156)/6 = 36-26= 10 km/hr = current speed

check the answers

6(36-10) = 6(26 = 156

6(36+10) = 6(46) = 276