one pump, let's call it A, fills the reservoir by 1/60 every hour. Now, B fills it by 1/80 every hour. C empties it by 1/90 every hour. All three are on, so now we combine them into one function: t(1/60 + 1/80 - 1/90) = 1, where t = the time it takes to fill it, and 1 is just our "reservoir finally filled" marker.
isolate t onto one side and we see t = 720/13 exactly, or approximately 55.38 hours. let me know if this is the wrong answer but I'm pretty sure it is correct!
Answer:
c = 15/2
Step-by-step explanation:
Multiply both sides of the equation by 9, then reduce the fraction.
9(5/6) = c
15/2 = c
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<em>Alternate methods</em>
You are usually told to "cross-multiply" which means you multiply the expression by the product of the denominators. this would give you ...
9(5) = 6(c)
Then you would divide by the coefficient of c to get ...
(9·5)/6 = c = 15/2
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Since c is multiplied by 1/9, you can solve this by multiplying by the inverse of that coefficient, 9. That is what is done in the first section above. Usually, this does in one step what the "cross-multiply" method does in 2 steps.
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The "cross multiply" step can also be done by multiplying by the least common multiple of the denominators, 18. Then you have ...
18(5/6) = 18(c/9)
15 = 2c
Now, dividing by the coefficient of c gives ...
15/2 = c
25.00
-2.65
That is how you subtract 25 from 2.65
Answer:
6 crayons more
Step-by-step explanation:
At Dante's party, each child gets 192/16 = 12 crayons each
At Maria's party, each child gets 234/13 = 18 crayons each.
Therefore, each child at Maria's party gets 18-12 = 6 crayons more each than at Dante's party.
Answer:
43
Step-by-step explanation:
80-37 = 43
