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working together at their constant rates , A and B can fill [#permalink]
18 Jul 2008, 05:08

working together at their constant rates , A and B can fill an empty tank to capacity in1/2 hr.what is the constant rate of pump B? 1) A's constant rate is 25LTS / min 2) the tanks capacity is 1200 lts.

Last edited by arjtryarjtry on 18 Jul 2008, 07:08, edited 2 times in total.

1) we don't know the tanks capacity. We know the speed of a, but we can't figure how quickly A can fill it alone without the capacity.

2) We don't know the speed of either pump. The trick here is to forget the information from (1) and only use the info for (2) otherwise we'll likley answer B, when it should be C.

(Together) We can figure out how quickly A can fill the tank (48 minutes) and then from that we can figure out how fast B must be in order to make A + B = 30 minutes (or 2400 litres an hour)

arjtryarjtry wrote:

working together at their constant rates , A and B can fill an empty tank to capacity in1/2 hr.what is the constant rate of pump B? 1) A's constant rate is 25LTS / min 2) the tanks capacity is 1200 lts.

_________________

------------------------------------ J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.

working together at their constant rates , A and B can fill an empty tank to capacity in1/2 hr.what is the constant rate of pump B? 1) A's constant rate is 25LTS / min 2) the tanks capacity is 1200 lts.

C for me

(A+B)* 30 mins = X litres of water...(X)

1) A is 25 Lts/ min, in 1/2 hr A alone will fill the tank with 25 * 30 = 750 ltrs of water

Showoff! Going through and actually solving the problem. I guess I'm just too lazy! LOL Nice work alpha...as usual.

alpha_plus_gamma wrote:

arjtryarjtry wrote:

working together at their constant rates , A and B can fill an empty tank to capacity in1/2 hr.what is the constant rate of pump B? 1) A's constant rate is 25LTS / min 2) the tanks capacity is 1200 lts.

C for me

(A+B)* 30 mins = X litres of water...(X)

1) A is 25 Lts/ min, in 1/2 hr A alone will fill the tank with 25 * 30 = 750 ltrs of water

(X) leaves is with 2 unknowns, X and A...insuff

2) (A+B)* 30 mins = 1200 litres of water

A + B = 40 lts/min

two unknowns, A & B, insuff

Together

25 + B = 40

B = 15 lts/min

suff

_________________

------------------------------------ J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.

"Showoff" is slang for when someone is good at something and everyone else knows it, that person does something just so others can see them do it. It can sometimes be a bad thing, but I mean it as a joke. You're very good at quant and I am teasing you because you went through the problem and solved for B where I just stopped when I saw it could be solved and didn't bother going all the way.

I hope I didn't offend you. I sometimes forget that many people on here are non-native English speakers. So many people that have English as a second language write very well and I forget that some slang can easily be misunderstood.

alpha_plus_gamma wrote:

jallenmorris wrote:

Showoff!

What do u mean?

_________________

------------------------------------ J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.

Please remember that I intended this as a joke, and was having fun. Sometimes people will use the term "show off" to refer to someone they don't like or is acting in a way they don't like. I was using it in a teasing manner.
_________________

------------------------------------ J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.