Q&A - P5 Math

[tianzhu]

bbkoala:

100 workers were paid a total of $24750. If 25% of them received 20% more money than the remaining men, calculate the amount received by each man from the group who got less.

Ans is $150.

I can't get this value, and tried working backwards using $150, but couldn't get $24750.

Hi

25% ----- 25 workers
75% ------ 75 workers

The lower wage worker receives 1 unit each

75 units + 90 units (20% more) ------- 24750
165 units ----- 24650

1 unit ----- 150

Best wishes

[ozora]

need guide in these 2 questions

q1. http://i54.tinypic.com/119xzpv.jpg\">
q2. Apple and Berth had a total of $300 to spend.
Apple spent thrice of the amount she has left while Berth spent twice of the amount she has left. Given that the 2 total friends had a total of $90 left, how much did they have at first?

[ksme]

ozora:

need guide in these 2 questions

q1. http://i54.tinypic.com/119xzpv.jpg\">
q2. Apple and Berth had a total of $300 to spend.
Apple spent thrice of the amount she has left while Berth spent twice of the amount she has left. Given that the 2 total friends had a total of $90 left, how much did they have at first?

Is the answer for question 1 : 184?

Total area of non-shaded region = 240+56 = 296.
Therefore, area of shaded region = 480-296 = 184.

The error in your calculation is because of double counting 56 since area of 1 of the big triangle which is half of the rectangle is already inclusive of 1 of the 56.

Hope this is clear.

[ksme]

ozora:

need guide in these 2 questions


q2. Apple and Berth had a total of $300 to spend.
Apple spent thrice of the amount she has left while Berth spent twice of the amount she has left. Given that the 2 total friends had a total of $90 left, how much did they have at first?

Ozora,
Here's my working:
Let A be 1 unit of Apple's amount.
Let B be 1 unit of Berth's amount.

At the beginning : 4A + 3B = $300 ......(1)

At the end : A + B = S$90
=> 3A + 3B = $90 x 3 = $270..... (2)

Comparing (1) and (2) => A = $30

Since Apple has 4units at first, she will have $30 x 4 = $120

Total at first is $300. Therefore, Berth's share at first is $180.

My workings is not very elegant. Maybe others have a more elegant way to work this out.

Hope this helps.

[bbkoala]

Hi tianzhu


Thanks for your fast response.

Haha...to think that I finally understood the question after looking at your answer!

Lucky my gal asked me to post on KSP if I can't figure out the answer

[ozora]

ksme:

ozora:

need guide in these 2 questions


q2. Apple and Berth had a total of $300 to spend.
Apple spent thrice of the amount she has left while Berth spent twice of the amount she has left. Given that the 2 total friends had a total of $90 left, how much did they have at first?

Ozora,
Here's my working:
Let A be 1 unit of Apple's amount.
Let B be 1 unit of Berth's amount.

At the beginning : 4A + 3B = $300 ......(1)

At the end : A + B = S$90
=> 3A + 3B = $90 x 3 = $270..... (2)

Comparing (1) and (2) => A = $30

Since Apple has 4units at first, she will have $30 x 4 = $120

Total at first is $300. Therefore, Berth's share at first is $180.

My workings is not very elegant. Maybe others have a more elegant way to work this out.

Hope this helps.

thanks for both the answers. It is great help to me but the 2nd question involved in the use of algebra. The kids are not taught. is there any other method?

[ksme]

ozora:

thanks for both the answers. It is great help to me but the 2nd question involved in the use of algebra. The kids are not taught. is there any other method?

Ozora,
Think answer for Q2 is units method. Anyway, you can draw out the models and compare before and after model to get the same answer. I don't know how to draw models with my computer so maybe wait for some other parents to provide the model approach.

[ozora]

ksme:

ozora:

thanks for both the answers. It is great help to me but the 2nd question involved in the use of algebra. The kids are not taught. is there any other method?

Ozora,
Think answer for Q2 is units method. Anyway, you can draw out the models and compare before and after model to get the same answer. I don't know how to draw models with my computer so maybe wait for some other parents to provide the model approach.

sure thanks.

[MathIzzzFun]

ozora:

ksme:

[quote=\"ozora\"]need guide in these 2 questions


q2. Apple and Berth had a total of $300 to spend.
Apple spent thrice of the amount she has left while Berth spent twice of the amount she has left. Given that the 2 total friends had a total of $90 left, how much did they have at first?

Ozora,
Here's my working:
Let A be 1 unit of Apple's amount.
Let B be 1 unit of Berth's amount.

At the beginning : 4A + 3B = $300 ......(1)

At the end : A + B = S$90
=> 3A + 3B = $90 x 3 = $270..... (2)

Comparing (1) and (2) => A = $30

Since Apple has 4units at first, she will have $30 x 4 = $120

Total at first is $300. Therefore, Berth's share at first is $180.

My workings is not very elegant. Maybe others have a more elegant way to work this out.

Hope this helps.

thanks for both the answers. It is great help to me but the 2nd question involved in the use of algebra. The kids are not taught. is there any other method?[/quote]Hi

hope this helps.. the kids were taught to solve the \"stars & moons\" sums in P1/P2 which is really algebra in pictorial form..

http://i53.tinypic.com/25ztdfa.jpg\">


cheers.

[tianzhu]

bbkoala:

Hi tianzhu


Thanks for your fast response.

Haha...to think that I finally understood the question after looking at your answer!

Lucky my gal asked me to post on KSP if I can't figure out the answer

Hi

Good Morning.

You're welcome.

Best wishes