SOLUTION: A boy can swim down stream four times as fast as he swim up stream. If he can swim up stream and down stream in a total of 22 minutes, how many minutes does it takes him to swim up

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Question 792848: A boy can swim down stream four times as fast as he swim up stream. If he can swim up stream and down stream in a total of 22 minutes, how many minutes does it takes him to swim upstream
Found 2 solutions by ankor@dixie-net.com, amalm06:
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
A boy can swim down stream four times as fast as he swim up stream.
If he can swim up stream and down stream in a total of 22 minutes, how many minutes does it takes him to swim upstream.
:
let the one-way distance = 120 m
let s = his speed up stream
then
4s = his speed downstream
;
Write a time equation time = dist/speed
:
Upstr time + downstr time = 22 min
+ = 22
Multiply eq by 4s to clear the denominators
4(120) + 120 = 4s(22)
480 + 120 = 88s
s = 600/88
s = 6.82 m/min his upstream speed
find the time upstream
120/6.82 = 17.6 min to swim upstream
:
Check this by finding the time down stream
120/(4*6.82) = 4.4 min
Total time 4.4 + 17.6 = 22 min

Answer by amalm06(224) (Show Source):
You can put this solution on YOUR website!
Upstream: d=(r)(t1)
Downstream: d=(4r)(t2)
(r)(t1)=(4r)(t2)
t1=(4)(t2)
t2=22-t1
t1=(4)(22-t1)
t1=88-(4)(t1)
(5)(t1)=88
t1=88/5 min (Answer)