Q&A - P5 Math

[Udon]

Need your help to check ....Is my calculation right?

Thank you...

Q1. Matthew saved 1/5 of his monthly salary. He spent 3/8 of the remaining money on transport and the rest on food and other expenses. What fraction of his salary did he spend on food and other expenses?

Salary - 5/5 - 1/5 = 4/5

Spent - 3/8 (on transport)
Spent - 5/8 (on food & other expenses)

Fraction of his salary - 5/8 x 4/5 = 1/2 ?

Regards
Udon

[Dad8282]

Udon:

Need your help to check ....Is my calculation right?

Thank you...

Q1. Matthew saved 1/5 of his monthly salary. He spent 3/8 of the remaining money on transport and the rest on food and other expenses. What fraction of his salary did he spend on food and other expenses?

Salary - 5/5 - 1/5 = 4/5

Spent - 3/8 (on transport)
Spent - 5/8 (on food & other expenses)

Fraction of his salary - 5/8 x 4/5 = 1/2 ?

Regards
Udon

Hi Udon,

Yes, your answer is correct.

[zombie]

Thanks for the solution

[Dad8282]

Hi,


Need help with below Q:

Catholic High 2011 SA 2 P2:
Q14. Aaron and Ben shared a sum of $200. Aaron gave 3/5 of what he has to Ben. Ben later gave 1/5 of what he has back to Aaron. They ended up wtih equal amount of money. How much did Aaron have at first?

Thanks.

[terilyn]

This is tough, please help :imdrowning:


http://i45.tinypic.com/96ayb5.jpg\">

Thanks a Million in advance

[zeemimi]

Dad8282:

Hi,


Need help with below Q:

Catholic High 2011 SA 2 P2:
Q14. Aaron and Ben shared a sum of $200. Aaron gave 3/5 of what he has to Ben. Ben later gave 1/5 of what he has back to Aaron. They ended up wtih equal amount of money. How much did Aaron have at first?

Thanks.

End:
A has 4u
B has 4u

before Ben gave 1/5 to Aaron
A has 3u
B has 5u

before Aaron gave 3/5 to Ben
A has 7.5u
B has 0.5u

8u -> 200
1u -> 25
A has 7.5u = $187.50

[Dad8282]

:thankyou:, zeemimi

[MathIzzzFun]

terilyn:

This is tough, please help :imdrowning:


http://i45.tinypic.com/96ayb5.jpg\">

Thanks a Million in advance

(For MD, just replace units with blocks ... )

Banana muffins --> 12 units,
Left --> 3 units

Chocolate muffins --> 12 units + 864,
Left --> 5/6 x (12 units + 864) = 10 units + 720

So,
10 units + 720 = 3 units + 1728
1 unit --> 144

Chocolate muffins, at first --> 12 x 144 + 864 = 2592

cheers.

[zombie]

Hello, Is my working acceptable ? I am teaching my son, just need to know if this approach is acceptable ?

Thanks in advance to any kind soul who can help me, SA2 next week.
Please recommend me a good Maths tutor for next year PSLE.
I'm struggling to teach my dd, just pm me will do.

question
Mr Chen bought some pencil cases and bags for the children at a gathering. The price of each pencil case was $ 2.40 while the price of each bag $10.80. For every 4 bags bought, he was given one such pencil case for free. After receiving the free pencil cases the number of pencil cases was 1/3 of the number of bags bought. If Mr Chen paid $1584 how much did he pay for the bags more than the pencil cases.

I use my own guess and check, and manage to solve.

solution
1 set of 4 bags + 1 pencil free → $10.80 x 4 = $43.20

$1584 ÷ $43.20 → maximum no of sets → 36 sets + ‘must buy’ no of pencil cases.

Thus, $1584 – (36 x $43.20) = $28.80
$1584 - $1555.20 = $1526.40

Answer $1526.40

Check if it is correct !
$28.80 ÷ $2.40 = 12 ‘must buy’ no of pencil cases
12 + 36 free pencil cases → 48

No of bags 36sets x 4(in a set) → 144

number of pencil cases : the number of bags bought.
48 : 144
1: 3

[MathIzzzFun]

zombie:

Hello, Is my working acceptable ? I am teaching my son, just need to know if this approach is acceptable ?

Thanks in advance to any kind soul who can help me, SA2 next week.
Please recommend me a good Maths tutor for next year PSLE.
I'm struggling to teach my dd, just pm me will do.

question
Mr Chen bought some pencil cases and bags for the children at a gathering. The price of each pencil case was $ 2.40 while the price of each bag $10.80. For every 4 bags bought, he was given one such pencil case for free. After receiving the free pencil cases the number of pencil cases was 1/3 of the number of bags bought. If Mr Chen paid $1584 how much did he pay for the bags more than the pencil cases.

I use my own guess and check, and manage to solve.

solution
1 set of 4 bags + 1 pencil free → $10.80 x 4 = $43.20

$1584 ÷ $43.20 → maximum no of sets → 36 sets + ‘must buy’ no of pencil cases.

Thus, $1584 – (36 x $43.20) = $28.80
$1584 - $1555.20 = $1526.40

Answer $1526.40

Check if it is correct !
$28.80 ÷ $2.40 = 12 ‘must buy’ no of pencil cases
12 + 36 free pencil cases → 48

No of bags 36sets x 4(in a set) → 144

number of pencil cases : the number of bags bought.
48 : 144
1: 3

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In the end,
pencil cases: bags = 1:3 --> 4u : 12u
since 1 free pencil case is given for every 4 bags bought,
number of free pencil cases given free = 12u/4 = 3u
So, number of pencil case bought : bags bought --> 1u : 12u

for every set of 1 pencil case and 12 bags
Total amount = 1 x $2.40 + 12 x $ 10.80 = $132
12 x $10.80-$2.40 = $127.20 --> paid $127.20 more for bags for every set of 1 pencil & 12 bags

$1584/ $132 = 12 --> 12 sets of (1 pencil + 12 bags)
12 x $ 127.20 =$1526.40 --> MR Chen paid $1526.40 more for the bags than the pencil cases.

cheers.