Math Question

[Rayleigh]

Hi, I need help for a Math question for a P5 level.

 

A and B shared $425. After A spent 2/3 of his money and B spent 1/4 of his money, B had twice as much money as A. Find the amount of B had in the end.

 

Thanks in advance.

 

Anyone knows the unitary/equivalent method?

Edited August 8, 2013 by Rayleigh

[Rayleigh]

Double post. Deleted

Edited August 8, 2013 by Rayleigh

[Watodo]

2(A - 2/3A) = B - 1/4B

2A - 4/3A = B - 1/4B

2/3A = 3/4B

A = 9/8B

 

If A + B = 425

 

9/8B + B = 425

17/8B = 425

B = 200

 

To find out how much B has left = 3/4B = 200 * 3/4 = 150.

[Pisces69]

Hi, I need help for a Math question for a P5 level.

 

A and B shared $425. After A spent 2/3 of his money and B spent 1/4 of his money, B had twice as much money as A. Find the amount of B had in the end.

 

Thanks in advance.

 

Anyone knows the unitary/equivalent method?

 

 

Did A n B share the money equally ie. 50/50?

[Pisces69]

2(A - 2/3A) = B - 1/4B

2A - 4/3A = B - 1/4B

2/3A = 3/4B

A = 9/8B

 

If A + B = 425

 

9/8B + B = 425

17/8B = 425

B = 200

 

To find out how much B has left = 3/4B = 200 * 3/4 = 150.

 

 

Clap clap clap..

[Throttle2]

Hi, I need help for a Math question for a P5 level.

 

A and B shared $425. After A spent 2/3 of his money and B spent 1/4 of his money, B had twice as much money as A. Find the amount of B had in the end.

 

Thanks in advance.

 

Using logic , you will find that :-

 

since 2/3A = 3/4B

then 8A = 9B

 

meaning there are 17 equal parts (25 X 17 = 425)

 

here is the tricky portion.

base on the equation that 8A = 9B, it means that A is bigger than B becos less of A is more of B

 

so:-

A had $225 to begin

B had $200 to begin

 

After A spent 2/3 (which is $150 out of $225) and B spent 1/4 (which is $50 out of $200), B had $150 which is twice of A's $75.

 

Answer B has $150 left in the end.

 

 

Sorry ,my maths not so good, so i solve purely out of logicial thing.

[Asd78]

Using logic , you will find that :-

 

since 2/3A = 3/4B

then 8A = 9B

 

meaning there are 17 equal parts (25 X 17 = 425)

 

here is the tricky portion.

base on the equation that 8A = 9B, it means that A is bigger than B becos less of A is more of B

 

so:-

A had $225 to begin

B had $200 to begin

 

After A spent 2/3 (which is $150 out of $225) and B spent 1/4 (which is $50 out of $200), B had $150 which is twice of A's $75.

 

Answer B has $150 left in the end.

 

 

Sorry ,my maths not so good, so i solve purely out of logicial thing.

 

I think this is what the P5 students should be learning instead of the Simultaneous Equation....and they have to use diagram to solve it...

[Rayleigh]

Hi all, thank you very much. Understood the solutions. Have manage to convert one of the two solutions into Equal Fraction method ler. It goes like this. Pretty similar for Bro Gold Rolex method :-) but express differently:

 

Money Balance:

 

A -> 1/3

B -> 3/4

 

Ratio:

 

B money = 2 x A money

 

Therefore

3/4 B money = 2 x 1/3 A money

3/4 B money = 2/3 A money

 

Making the numerator of A and B to be equal, the common factor is 6

 

3/4 B money x (2/2) = 2/3 A money x (3/3)

6/8 B money = 6/9 A money

 

Total units of A and B = 8u + 9u = 17u

Total money = $425

1 unit = 425/17 = $25

 

Hence B has 6 units = 6 x $25 =$150.

 

 

 

Once again, thank you all.

 

 

 

 

 

 

 

 

[Xtraz]

Given

A: 1 U

B: 2 U = 3 Units

 

Therefore 1 U = 1.5 units

At first, A has 3 U = 1.5 x 3 = 4.5 Units

Total A + B = 425

4.5 Units + 4 Units = 425

8.5 Units = 425

1 unit = 50

Amt B had in the end = 3 units = 3 x 50 = $150 (ans)

 

 

 

 

[Muddy]

[Wind30]

A word of advice....

 

don't bother "teaching" how to solve such questions to your child...

 

The best way is let the kid think through the problem themselves... trust me. Teaching them is not very useful.

 

If they can't solve it now, let them think longer.... maybe motivate them with some rewards (praise, gifts, etc) once they succeed. I think the most impt thing is to cultivate their own determination to solve the "hard" problems THEMSELVES.

 

 

 

[Mcf777]

 

 

Bro, using diagram should be the right way.

 

but how do you know that A is cut into 9 parts and B into 8 parts?

 

thanks.

[Muddy]

[Muddy]

[Duckduck]

A word of advice....

 

don't bother "teaching" how to solve such questions to your child...

 

The best way is let the kid think through the problem themselves... trust me. Teaching them is not very useful.

 

If they can't solve it now, let them think longer.... maybe motivate them with some rewards (praise, gifts, etc) once they succeed. I think the most impt thing is to cultivate their own determination to solve the "hard" problems THEMSELVES.

 

correct. teaching is short way out. making them thk is correct n longer way

[Mcf777]

bro muddy, thanks for the explaination

[BlueOldMan]

Clap clap clap..

Clapping for his avatar right

[Pisces69]

Clapping for his avatar right

 

 

Too small. Cant see anything.