math help

[bosoxfan]

with no regard for how stupid this will make me look.

Pump A can fill a tank in 5 hours
Pump B can fillthe same tank in 4 hours
If both pumps run together how long will it take to fill the tank?

What is the formula to solve this?

[jstnrgrs]

You are stupid. Obviously 9 hours.

[Isura]

Need more information. Do the pumps fill the tanks at a constant rate? If so, this problem is pretty easy. Do you see why?

[Isura]

[ QUOTE ]
You are stupid. Obviously 9 hours.

[/ QUOTE ]

I hope you are joking.

[Huskiez]

Pump A fills 1 tank per 5 hours, or 1/5 tank per hour.
Pump B fills 1 tank per 4 hours, or 1/4 tank per hour.

Pump A and B together fill (1/5 + 1/4) = 9/20 tank per hour.

You need to fill one tank.

1 tank * 20 hours / 9 tanks = 20/9 hours.

[jason_t]

[ QUOTE ]
[ QUOTE ]
You are stupid. Obviously 9 hours.

[/ QUOTE ]



I hope you are joking.

[/ QUOTE ]

[mostsmooth]

pump a fills 1/5 the tank per hour
pump b fills 1/4 the tank per hour
together they would fill 9/20 the tank per hour
to fill the tank together would be 20/9 hours
/images/graemlins/cool.gif

[bosoxfan]

yes.
i'm not really looking for the answer but the formula to get the answer. i figured it was easy and yet i still don't know.

[jstnrgrs]

Pump A fills at a rate of .2 tank/hour.
Pump B fills at a rate of .25 tank/hour.
Together they fill at a rate of .45 tank/hour.
rate x time = distance.
time = 1tank / .45t/h = 2.2222222222hours.

[M2d]

rate(a) + rate(b)=rate(combined).

[BillNye]

[ QUOTE ]
Pump A fills at a rate of .2 tank/hour.
Pump B fills at a rate of .25 tank/hour.
Together they fill at a rate of .45 tank/hour.
rate x time = distance.
time = 1tank / .45t/h = 2.2222222222hours.

[/ QUOTE ]

You Suck!

[Gamblor]

Here's the rationale:

Let x be the number of hours it takes for the tank to fill given a rate of flow of the water from pump a. Rate of flow for pump a = 1/5 tank an hour. For pump b, 1/4 tank an hour.

Thus, 1 = x(a) When a = 1/5, x = 5.

So 1 = x(1/5 + 1/4) = x(4/20 + 5/20) = 9x/20

1 = 9x/20

20 = 9x

x = 20/9 hrs.

The tank will fill in 20/9 or 2 2/9 hours.

[istewart]

STOP
SAYING
DO YOU SEE WHY

[jason_t]

[ QUOTE ]
with no regard for how stupid this will make me look.

Pump A can fill a tank in 5 hours
Pump B can fillthe same tank in 4 hours
If both pumps run together how long will it take to fill the tank?

What is the formula to solve this?

[/ QUOTE ]

As someone who frequently teaches math, I would rather guide you towards a correct solution rather than just give you the answer.

Questions:
1. How much of the tank does pump A fill in one hour?
2. How much of the tank does pump B fill in one hour?
3. How much of the tank do pump A and pump B fill in one hour? (Having answered 1. and 2., you can answer this question.)
4. How loes does it tank for the pumps to jointly fill the tank?

[bosoxfan]

thank you

[Gamblor]

good god oot is fast.

we're all big nerds, by the way.

[jstnrgrs]

[ QUOTE ]
You Suck!

[/ QUOTE ]

I don't see why. If I had said:
[ QUOTE ]
Pump A fills at a rate of .2 tank/hour.
Pump B fills at a rate of .25 tank/hour.
Together they fill at a rate of .45 tank/hour.
rate x time = distance.
time = 1tank / .45t/h = 2.2222222222hours
pwned

[/ QUOTE ]

then your statement might be justified.

[bosoxfan]

[ QUOTE ]
As someone who frequently teaches math, I would rather guide you towards a correct solution rather than just give you the answer.

Questions:
1. How much of the tank does pump A fill in one hour?
2. How much of the tank does pump B fill in one hour?
3. How much of the tank do pump A and pump B fill in one hour? (Having answered 1. and 2., you can answer this question.)
4. How loes does it tank for the pumps to jointly fill the tank?


[/ QUOTE ]

I must remind you of the dim student who sits in the back of class. /images/graemlins/blush.gif

[istewart]

jason_t = wannabe mathematician /images/graemlins/wink.gif

[chaas4747]

I know there are many ways to skin a cat. But I think the formula that I learned for this is

(A * B)/(A + B) = x

You would still get 20/9 so it is all a wash.

[BillNye]

[ QUOTE ]
[ QUOTE ]
You Suck!

[/ QUOTE ]

I don't see why. If I had said:
[ QUOTE ]
Pump A fills at a rate of .2 tank/hour.
Pump B fills at a rate of .25 tank/hour.
Together they fill at a rate of .45 tank/hour.
rate x time = distance.
time = 1tank / .45t/h = 2.2222222222hours
pwned

[/ QUOTE ]

then your statement might be justified.

[/ QUOTE ]

and what was justified about my statement that got "you sucked"?

[jstnrgrs]

But do you know why that formula works? That's what's important.

[chaas4747]

Only if you work at a gas station!

[jakethebake]

you're surfing on your phone while taking the SATs right now aren't you? /images/graemlins/grin.gif

[dtbog]

I like your line.. but I might checkraise the turn here. You want to get that extra bet.

-DB

[jstnrgrs]

I just did a quick search of my posts over the last few days, and as far as I can tell, I never posted "You Suck!" in response to one of your posts.

[housenuts]

5^2 (25) + 4^2 (16) = 41. subtract 1 because they are only trying to fill one tank. = 40. divide by 2 because the pumps will be acting together to fill a tank. = 20 hours.

5^2 (25) - 4^2 (16) = 9 tanks

20 hours per 9 tanks

or 2.2222222 hours per tank

[bosoxfan]

yes, i get why that works thanks again.

[bosoxfan]

[ QUOTE ]
you're surfing on your phone while taking the SATs right now aren't you?

[/ QUOTE ]

nice

[kyro]

[ QUOTE ]
Need more information. Do the pumps fill the tanks at a constant rate? If so, this problem is pretty easy. Do you see why?

[/ QUOTE ]

If he saw why, he wouldn't be asking the question, douche.

[jason_t]

[ QUOTE ]
I must remind you of the dim student who sits in the back of class. /images/graemlins/blush.gif

[/ QUOTE ]

That's me in the back of my graduate classes.

[JaBlue]

good luck with that new SAT!