linear equations word problem

Question

A rowing team rowing with the current traveled 40 km in 2 h. Rowing against the current, the team could travel only 16 km in 2 h. Find the team's rowing rate in calm water and the rate of the current

Answer 1

Let r be the team's rowing rate in calm water.

Let c be the rate of the current

 

 

When rowing with the current, the rate is r + c and we can calculate it to be (40/2) km/hr or 20 km/hr

 

When rowing against the current, the rate is r-c and we can calculate it to be (16/2) km/hr or 8 km/hr

 

 

Therefore the system is     r + c = 20

                                       r -  c = 8

 

Combining the equations,  2r     = 28

                                        r      = 14

 

Plugging back in,  c = 6. You can now answer the questions.