SOLUTION: A bucket can be filled in 3 min. by the hot water tap, and 70 sec. by the cold water tap. Determine time taken to fill the bucket if both taps run with the same pressure as when t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A bucket can be filled in 3 min. by the hot water tap, and 70 sec. by the cold water tap. Determine time taken to fill the bucket if both taps run with the same pressure as when t      Log On


   

Question 1041335: A bucket can be filled in 3 min. by the hot water tap, and 70 sec. by the cold water tap. Determine time taken to fill the bucket if both taps run with the same pressure as when they are open singly.

3 min. = 180 sec.
Let x = time.
How do I proceed?
Non-homework question.
Found 2 solutions by josmiceli, ikleyn:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Rate of filling with hot water tap:
[ 1 bucket filled ] / [ 3 min ]
Rate of filling with cold water tap:
[ 1 bucket filled ] / [ 70/60 min ]
---------------------------
Add the 2 rates of filling to get the rate
with both taps open
Rate with both taps open:
[ 1 bucket filled ] / [ t min ]
---------------------------
+1%2F3+%2B+1%2F%287%2F6%29+=+1%2Ft+
+1%2F3+%2B+6%2F7+=+1%2Ft+
Multiply both sides by +21t+
+7t+%2B+18t+=+21+
+25t+=+21+
+t+=+21%2F25+ min
+%28+21%2F25+%29%2A60+=+50.4+ sec
---------------------
the bucket is filled in 50.4 sec
with both taps open
-----------------
check:
+1%2F3+%2B+1%2F%287%2F6%29+=+1%2Ft+
+1%2F3+%2B+1%2F%287%2F6%29+=+1%2F.84+
+.333+%2B+.8571+=+1.1905+
+1.1904+=+1.1905+
error due to rounding off

Answer by ikleyn(52835) About Me  (Show Source):
You can put this solution on YOUR website!
.
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