Q&A - P4 Math

[mathfreak]

Superbugs:

mathfreak:

[quote=\"Superbugs\"]Pls assist on this question:


Janice's age is a multiple of 7. Next year, her age will be a multiple of 4. If Janice is less than 40 years old, how old is she now?

This year: Multiple of 7
7,14,21,28,35
Next year: Multiple of 7
4,8,12,16,20,24,28,32,36
==> If compared to this year
3,7,11,15,19,23,27,31,35

My son asked why not 7 but 35?

This question actually has two answers. One is 7, and the other is 35. 7+1=8, a multiple of 4. 35+1=36, a multiple of 4. For the question to have only one solution, \"multiple of 4\" should be changed to \"multiple of 8\".

Tks a lot! Question is vague![/quote]You're welcome.

[visitor]

Need help…

Sharon baked between 10 and 20 muffins. If she packed them in bags of 4, she would have 2 muffins left. If she packed them in bags of 5, she would have short of 1 muffin. How many muffins did she baked?

Do we need to apply any modelling to solve this qn? Thks…

[MathIzzzFun]

visitor:

Need help....

Sharon baked between 10 and 20 muffins. If she packed them in bags of 4, she would have 2 muffins left. If she packed them in bags of 5, she would have short of 1 muffin. How many muffins did she baked?

Do we need to apply any modelling to solve this qn? Thks...

hi

using MD ...

http://i43.tinypic.com/etwms7.jpg\">

cheers.

[visitor]

I m lost.......it's time that I should send my son for Maths tuition


Thanks for your help!

[babies]

Hi, need to double check.:)


Q)
Tin jin saved $3500 in April. His monthly salary is twice the amount he saved in April.
He saved $4200 less than the amount he spent in May. How much ddi he save in May?

Is $2800 (saved in May) correct?

[MathIzzzFun]

babies:

Hi, need to double check.:)


Q)
Tin jin saved $3500 in April. His monthly salary is twice the amount he saved in April.
He saved $4200 less than the amount he spent in May. How much ddi he save in May?

Is $2800 (saved in May) correct?

Hi

spent $5600 & saved $1400 in May.

Salary --> $3500x 2 = $ 7000
In May,
saved --> 1 unit
spent --> 1 unit + $4200
2 units + $4200 = $7000
1 unit --> $1400, spending in May --> $5600

cheers.

[babies]

MathIzzzFun:

babies:

Hi, need to double check.:)


Q)
Tin jin saved $3500 in April. His monthly salary is twice the amount he saved in April.
He saved $4200 less than the amount he spent in May. How much ddi he save in May?

Is $2800 (saved in May) correct?

Hi

spent $5600 & saved $1400 in May.

Salary --> $3500x 2 = $ 7000
In May,
saved --> 1 unit
spent --> 1 unit + $4200
2 units + $4200 = $7000
1 unit --> $1400, spending in May --> $5600

cheers.

Hi MathIzzzFun,

Well noted & thank you! :rahrah:

[Superbugs]

Steve bought some 20cent and 50cent stamps for $32. The number of 20cent stamps he bought was 1/1/2 times the number of 50cent stamps. How many 20cent stamps did he buy?


Let x be no of 20cents coins and y be no of 50cents coins
Equation 1:
0.20x + 0.50y = 32
2x+5y=320

Equation 2:x=1/1/2y
2(3/2y)+5y=320
8y=320
y=40
Therefore x=60
My kid can understand this after I have done through but this is algebra which he will not learn till P6.
Any other method to solve this question fast and easy to understand?
We tried model method but cannot get the answers. Pls help. Tks

[MathIzzzFun]

Superbugs:

Steve bought some 20cent and 50cent stamps for $32. The number of 20cent stamps he bought was 1/1/2 times the number of 50cent stamps. How many 20cent stamps did he buy?


Let x be no of 20cents coins and y be no of 50cents coins
Equation 1:
0.20x + 0.50y = 32
2x+5y=320

Equation 2:x=1/1/2y
2(3/2y)+5y=320
8y=320
y=40
Therefore x=60
My kid can understand this after I have done through but this is algebra which he will not learn till P6.
Any other method to solve this question fast and easy to understand?
We tried model method but cannot get the answers. Pls help. Tks

Hi

20 cents stamps is 1 1/2 times 50 cents stamps, for 3 20-cents stamps for every 2 50-cents stamps.

Consider 1 packet of 3 x 20-cents stamps + 2 x 50-cents stamps.
Amount paid for this packet = $ 0.60 + $1.00 = $1.60

So, how many packets can you buy with $32 ? -- > $ 32 / $ 1.60 = 20 packets

Number of 20-cents stamps bought --> Number of packets x number of 20-cents stamps in 1 packet = 20 x 3 = 60
Number of 50-cents stamps bought --> Number of packets x number of 50-cents stamps in 1 packet = 20 x 2 = 40

cheers.

[trytry]

Please help to clarify this type of question.

Alice bought 2 similar cakes. She ate 1/3 of a cake. What fraction of the cakes was left?

Will the answer be the same if the question is "What fraction of a cake was left?"

TIA.