a boats crew rowed 20 miles downstream , with the current , in 2 hours. the return trip upstream , against the current , covered the same distance , but took 5 hours.

the crew rowing rate in still water is ? miles per hour

the rate of the current is ? miles per hour

Question

a boats crew rowed 20 miles downstream , with the current  , in 2 hours. the return trip upstream , against the current , covered the same distance , but took 5 hours. 

the crew rowing rate in still water is ? miles per hour

the rate of the current is ? miles per hour

anonymous · Answer

$Rate.Speed=\frac{spead1 + spead2}{2}$
speed1 = 20/2=10 mile per hour
speed2= 20/5=4 mile per hour
$Rate.Speed=\frac{10 +4}{2}= 7 ...MilePerHour$
you are welcome

anonymous · Answer

The Rate of the current :
let B : Boat speed
r : river speed

10 = B +r ..............1
4=B-r.....................2

solve 1 and 2 to get 

B = 7 ... which is obtained before 
r = 3 mile per hour which is the current speed