Q&A - P3 Math

[Dharma]

wahwah:

Can someone help me with the following P3 Math problem sum? Many thanks in advance.


Bob has thrice as many buttons as Ali. Ali has 179 buttons lesser then Carlos. Carlos has 228 buttons more than Ali and Bob. How many buttons do the three boys have altogether?

Hi,

Think there's something wrong with your Qn. How can Carlos have 179 buttons more than Ali when the next sentence says that Carlos has 228 more buttons than Ali and Bob?

[Muffins]

wahwah:

Can someone help me with the following P3 Math problem sum? Many thanks in advance.


Bob has thrice as many buttons as Ali. Ali has 179 buttons lesser then Carlos. Carlos has 228 buttons more than Ali and Bob. How many buttons do the three boys have altogether?

Hi wahwah, I think the question is a little wrong as, when I try to work it out, I keep getting thhat 1 unit is equal to 4 units + 48. Could you please get back to us on this? Thanks!

[wahwah]

Hi Muffins and Dharma,

Thanks for trying out the question. That was the question on my son’s holiday assignment paper. Will have to wait for the new term to verify with the teacher. Will update again.

[Muffins]

wahwah:

Hi Muffins and Dharma,

Thanks for trying out the question. That was the question on my son's holiday assignment paper. Will have to wait for the new term to verify with the teacher. Will update again.

Thanks for the heads-up wahwah!

[Devnahouse]

Hello,

Can help me solve this one.

The cost of 7 erasers and 3 rulers is $5.05.
The cost of 2 erasers and 6 rulers is $3.95
Find the cost of 2 erasers and 2 rules.

Many thanks.

[corneyAmber]

The cost of 7 erasers and 3 rulers is $5.05.

The cost of 2 erasers and 6 rulers is $3.95
Find the cost of 2 erasers and 2 rules.

7 erasers + 3 rulers = 5.05 --------(1) x 2
14 erasers + 6 rulers = 10.1 --------(2)
2 erasers + 6 rulers = 3.95 ---------(3)

(2)-(3),
12 erasers = 6.15
2 erasers = 1.025
Then 6 rulers = 3.95-1.025 = 2.925
2 rulers = 0.975

So 2 erasers + 2 rulers = 1.025 + 0.975 = $2

or (1) + (2)
9 erasers + 9 rulers = $9
2 erasers + 2 rulers = $2 (proportionately)

[Devnahouse]

ksi:

The cost of 7 erasers and 3 rulers is $5.05.

The cost of 2 erasers and 6 rulers is $3.95
Find the cost of 2 erasers and 2 rules.

7 erasers + 3 rulers = 5.05 --------(1) x 2
14 erasers + 6 rulers = 10.1 --------(2)
2 erasers + 6 rulers = 3.95 ---------(3)

(2)-(3),
12 erasers = 6.15
2 erasers = 1.025
Then 6 rulers = 3.95-1.025 = 2.925
2 rulers = 0.975

So 2 erasers + 2 rulers = 1.025 + 0.975 = $2

or (1) + (2)
9 erasers + 9 rulers = $9
2 erasers + 2 rulers = $2 (proportionately)

Thanks ksi. But I do not how to explain this simultaneous equation to a P3

My initial solution is :
7 Erasers + 3 Rulers = $5.05
2 Erasers + 6 Rulers = $ 3.95

Add them together we have
9 Erasers + 9 Rulers = $5.05 + 3.95 = $9

Each set of 1 Eraser 1 Ruler = $1
Therefore 2 sets of Eraser & Ruler = $2.

I'm thinking since the question ask for the price of 2 sets, the working out of each price is not necessary.

Anyone to shed some lights? Thanks in advance.

[corneyAmber]

Actually the second method i gave is the same as yours and it is not necessary to find the cost for 1, you can directly give the answer for 2 of each item.


Also in method 1, I was not thinking of simultaneous equation, I was using common sense but I guess it looked like simultaneous equation. :lol:

[Dharma]

Devnahouse:

Hello,

Can help me solve this one.

The cost of 7 erasers and 3 rulers is $5.05.
The cost of 2 erasers and 6 rulers is $3.95
Find the cost of 2 erasers and 2 rules.

Many thanks.

http://www.postimage.org/image.php?v=TsKNGfA

[Devnahouse]

Dharma, Thanks for taking time to explain in model form. Thanks ksi for your further clarifications. Appreciated.