tana rode a boat 1 km upstream in and hour. rowing at the same rate, she made the return trip downstream in 15 minutes. find the rate of the current

Answer 1

tana's rate -- x km/h
current rate -- y km/h

1(x-y) = 1
(1/4)(x + y) = 1 or x+y = 4
add them
2x = 5
x = 5/2
then y = 3/2

rate of current is 1.5 km/h

Answer 2

let v be her rowing velocity in still water, r be the velocity of the water.

1km=(v-r)*1hr
1km=(v+r)*.25hr

multipy the second equation by 4

4km=(v+r)1

now add the equations..
5km=2v and you have v = 2.5km/hr
so r must be 1.5km/hr (see equation 1)