A little math help please?

Discussion in 'General Discussion' started by wrecker, Jan 27, 2008.

  1. wrecker

    wrecker Particle man

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    Ok here is the problem



    brent lent his bro bob some money at 8% simple interest and he lent his sis betty half as much money at twice the intrest rate.

    Both loans are for 1 year. If brent made a total of .24 cents in interest, then how much did he lend to each one.




    you don't have to tell me the answer just how to figure out the problem.

    thanks!
     
  2. MegaMoonMan

    MegaMoonMan www.megamoonman.com TFW2005 Supporter

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  3. RoboticPlanet

    RoboticPlanet Exclusively Exclusive

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    MMM's link should help you.

    Hints: It's a single variable equation. The interest Brent made is the sum of 2 products.
     
  4. cbff

    cbff Destroyer of Botcon

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    Interest = Principle x Rate x Time

    In this case, it's:

    Brents Interest = (Bob Principle x .08 x 1) + (Betty Principle x .16 x 1)

    So let's put this into an actual formula now:

    .24 = (A x .08 x 1) + [(1/2 x A) x .16 x 1)]

    Now distribute the variable:

    .24 = .08A + .08A

    Now combine:

    .24 = .16A

    Divide:

    .24 / .16 = A

    Answer for A is $1.50

    Now let's check the work by putting 1.5 in for A:

    .24 = (1.5 x .08 x 1) + [(1/2 x 1.5) x .16 x 1)]

    Simplify:

    .24 = .12 + .12

    .24 = .24

    Success! So the final answer is that Brent lent Bob $1.50 and Betty $0.75

    If you have any more Algebra questions, feel free to ask.
     
  5. Deceptikitty

    Deceptikitty all about the hasubandos

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    As Barbie said, "Math is hard." :( 
     
  6. Dark_Convoy

    Dark_Convoy Old Bastard Veteran

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    And so is Ken's ugh... yeah.
     
  7. Transbot90210

    Transbot90210 Banned

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    I wish I had the internet when I was in highschool.
     
  8. Ironhide2005

    Ironhide2005 PS3tag=DeaDPooLTFW

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    Me grimlock no bozo it just head hurts when me think!
     
  9. cbff

    cbff Destroyer of Botcon

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    Aw, come on! This was an easy one! :lol 
     
  10. Deceptikitty

    Deceptikitty all about the hasubandos

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    Ken doesn't even HAVE one!
     
  11. Boardwise

    Boardwise is scary - Sig Killer - M Super Mod

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    Try this one:

    A building has a heat loss coefficient of 17 kW/K and an effective thermal capacity of 1.8 GJ/K. The internal set point temperature is 20oC and the building is occupied for 12 hours per day (7 days per week) and has an installed plant capacity of 500 kW. For a mean monthly outdoor temperature of 7oC (when the preheat time, t3-t2 = 4.71 hours) determine the following:

    (i) The summation of all hourly indoor temperatures overnight
    (ii) the mean 24 hour indoor temperature
    (iii) the base temperature if mean gains are 90 kW
    (iv) monthly degree-days using Hitchin’s formula, assuming k = 0.71 and 31 days in the month
    (v) the fuel consumption for that month (assuming an overall plant efficiency of 0.75)
    (vi) The CO2 emissions for that month (take the CO2 factor as 0.19 kg/kWh)
     
  12. Bryan

    Bryan ΜΟΛΩΝ ΛΑΒΕ

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    I could give you the answer, but you'd only be hurting yourself when you took it.
     
  13. cbff

    cbff Destroyer of Botcon

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    I don't do energy. :p 
     
  14. a person

    a person Is not amused.

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    :lol 
     
  15. Boardwise

    Boardwise is scary - Sig Killer - M Super Mod

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    Actually, I know the answers.

    Chicken.
     
  16. Bryan

    Bryan ΜΟΛΩΝ ΛΑΒΕ

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    Just messing with you, guy :D 
     
  17. Omegatron

    Omegatron Mandatory Fun. Buy it now TFW2005 Supporter

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    Insufficient information. How many people are coming in and out through the day? What's the average occupancy rate? How much heat is lost through doors opening and closing by the occupants?

    Besides, this is more a physics problem than a math problem, as many physics formulae are involved.
     
  18. Boardwise

    Boardwise is scary - Sig Killer - M Super Mod

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    None of that information is needed actually.
     
  19. Ops_was_a_truck

    Ops_was_a_truck JOOOLIE ANDREWWWWWS!!!!!!

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    When you're done with Boardwise's problem, try this one:

    Two random variables X and Y have the joint PDF

    fxy(x,y) = 6x if x>0, 0<x+y <1 ...and 0 otherwise

    1. Find the marginal PDFs of X and Y
    2. Find the expected value E{XY}
    3. Find the probability of the event {X < 1/2, Y< 3/4}
     
    Last edited: Jan 30, 2008
  20. Bryan

    Bryan ΜΟΛΩΝ ΛΑΒΕ

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    Once upon a time I went to an engineering school...

    ...but I couldn't do that stuff then either.
     

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