Question

The answer is 10/3 mph, can someone help me with the equation? Sam can row 10 miles downstream in one third the time he can row 6 miles upstream. If Sam can row 5 miles per hour in still water, how fast is the current?

Answer 1

lets time him :)

in 1hour he can go 6 miles up; and in 1/3 hour he can go 10 miles down

or 10 down in and hour and 6 up in 3

Answer 2

s = d/t (=) t = s /v


so if you equalize the times,

10/(5+x) = 6/(3(5-x))
blablabla...
5+x=25-5x
20 = 6x
x = 10/3

Answer 3

t = d / s i meant

Answer 4

and ofc (5+x) is he swimming 5mph plus the current (x) and (5-x) is he swimming minus the current force

Answer 5

ok.. Step by step:

10 6 5+x 5-x 3 5+x 5-x
---- = ----- (=) ----- = ---- x -- (=) ----- = ----- (=) 5+x = 5(5-x)
5+x 3(5-x) 10 1 6 10 2

5+x = 5(5-x) (=) 5+x=25-5x (=) 20 = 6x (=) x = 10/3

Answer 6

awesome. Thank you much