SOLUTION: One computer requires 75 minutes to solve a complex math problem. A faster one requires 50 minutes for the same problem. How long would it take if both computers work together?

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Question 1133824: One computer requires 75 minutes to solve a complex math problem. A faster one
requires 50 minutes for the same problem. How long would it take if both computers
work together?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add their rates of working to get
their rate working together
1st rate:
[ 1 problem solved ] / [ 75 min ]
2nd rate:
[ 1 problem solved ] / [ 50 min ]
------------------------------------
Let +1%2Ft+ = their rate working together
in problems/min
+1%2F75+%2B+1%2F50+=+1%2Ft+
Multiply both sides by +150t+
+2t+%2B+3t+=+150+
+5t+=+150+
+t+=+30+
It takes them 30 min working together
--------------------------------------------
check:
+1%2F75+%2B+1%2F50+=+1%2F30+
+1%2F15+%2B+1%2F10+=+1%2F6+
+.06667+%2B+.1+=+.16667+
+.16667+=+.16667+
OK