Question 184813
"A motor boat took 5h to travel a distance of 60 km up a river" ___ so b-c=60/5 or 12


"The return trip took 3h" ___ so b+c=60/3 or 20


adding equations ___ (b-c)+(b+c) = 12+20 ___ 2b = 32 ___ b=16


substituting __ (16)+c = 20 ___ c = 4