Question

Can someone explain this for me step by step? Abby rows 10 km upstream and 10 km back in a total time of 3 hr. The speed of the river is 5 km/h. Find Abby’s speed in still water. @mark_o.

Answer 1

You found me lol

Answer 2

yeah im here now lol :D

Answer 3

she row from starting point A to B then from B to A

that is
time from A to B + time from B to A = 3 hours

Answer 4

ok

Answer 5

time

Tab + T ba = 3 (1) but distance d=velocity x time,. therefore t=d/v

dAB dBA
------ + ------- =3 but distances dBA=dAB=10 km
v v

10 10
------- + ------ =3
v v but note that velocity of river is v=5 km/hr
for upstream v= v+5
10 10 for down stream v= v-5, therefore
------- +------ = 3
v+5 v-5
you can algebra now ion finding v=?

Answer 6

i mean you can do the algebra now from this point ... :D

Answer 7

ummmm I am stuck

Answer 8

I am sorry lol

Answer 9

10/(v+5) + 10 /(v-5) =3

10(v-5) + 10(v+5)
------------------ =3
(v+5)(V-5)

Answer 10

do multiplication and addition to simplify the numerator and the denominator..:D

Answer 11

give me a sec

Answer 12

wow i suck cause I am lost