SOLUTION: A candy factory has a large vat into which workers pour chocolate and cream. Each ingredient flows into the vat from its own special hose, and each ingredient comes out of its hose

Question 346508: A candy factory has a large vat into which workers pour chocolate and cream. Each ingredient flows into the vat from its own special hose, and each ingredient comes out of its hose at a constant rate. Workers at the fatory know that it takes 20 minutes to fill the vat with chocolate from the chocolate hose, and it takes 15 minutes to fill the vat with cream from the cream hose. If workers pour both chocolate and cream into the vat at the same time (each coming full tilt out of its own hose). how long will it take to fill the vat? Before you find an exact answer to this problem find an approximate answer or find a range, such as "between and ...minutes," Explain your answer.
I also need to know the name of the strategy used to solve the problem.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Workers at the factory know that it takes 20 minutes to fill the vat with chocolate from the chocolate hose, and it takes 15 minutes to fill the vat with cream from the cream hose.
------
Chocolate hose rate: 1/20 job/min
Cream hose rate: 1/15 job/min
----
Together rate: 1/x job/min
---------------------------------
Equation:
rate + rate = together rate
1/20 + 1/15 = 1/x
-----------------
Multiply thru by 60x to get:
3x + 4x = 60
7x = 60
x = 60/7 minutes = 8 4/7 minutes (time to fill the vat together)
============================
Cheers,
Stan H.
RELATED QUESTIONS
A vat contains 4.7 l of ice cream. 65 cl is taken out and put into a tub. How many... (answered by mathsolverplus)

There are two vats of orange juice. After 10% of the orange juice in the first vat was... (answered by josmiceli)

There are 2 vats of orange juice. After 10% of the orange juice in the first vat is... (answered by josgarithmetic)

With only the small valve open, all of the liquid can be drained from a large vat in 4... (answered by ankor@dixie-net.com)

A certain factory products are made in vats that has a capacity to hold 70 quarts. Each... (answered by rfer)

You have a total supply of $1000$ pieces of candy, and an empty vat. You also have a... (answered by ikleyn)

Two equal sized vats, A and B containing 1000L of oil, are slowly being drained. Given... (answered by richwmiller)

Word problems are my toughest challenge. For example; Draining the vat. With only the... (answered by stanbon)

A vat of chocolate can be filled by an Intel pipe in 12 hours. An outlet pipe can empty... (answered by Boreal,ikleyn)