Q&A - P5 Math

[YumYum]

Dear Tianzhu,


Thank you and I take a look at previous posts.

[tianzhu]

YumYum:

3. Thomas spent 2/7 of his salary.
He gave 7/8 of the remaining to his wife and two children in the ratio of 16:2:3 and saved the rest.
He saved $420.
What fraction of his salary did he give to his children?

Hi

You may use the Branch Method for Q3.

You may refer to this solution for a similar question posted earlier.

I did a quick check and the answer is 25/168.

Best wishes.

http://farm8.staticflickr.com/7157/6580178853_c0e063bd36_z.jpg\">

[tianzhu]

YumYum:

Dear Tianzhu,


Thank you and I take a look at previous posts.

Hi

YumYum

You're welcome.

The previous posts refer to similar solutions for Q2 type of questions if you want more practice.

Best wishes

[tianzhu]

YumYum:

4. Darren placed 263 books on 3 shelves, labeled X, Y and Z.
After more books were placed onto shelf X and shelf Y, the number of books on shelf X increased by 27 and the number of books on shelf Y quadrupled.
20 books were then taken down from shelf Z.
As a result, there are now an equal number of books on each shelf.
Find the number of books on shelf x at first.

Hi

I’ll some pointers for MD.

In the end
Z ----- 4 units
Y ----- 4 units
X ------ 4 units

At first
Z ----- 4 units + 20
Y ----- 1 unit
X ------ 4 units – 27

9 units + 20 -27 ------ 263
9 units ----- 270

1 unit ----- 30

X ------ 120 – 27 ------93.

Best wishes

[tianzhu]

YumYum:

Qn 5.


2/5 of Stanley's marbles were equal to 7/9 of Timothy's marbles.
After Stanley gave 2/7 of his marbles to Timothy, and Timothy received 16 marbles from his brother, Stanley had 5/6 as many marbles as Timothy.

a. How many marbles did Timothy have in the end?
b. How many marbles did both boys have altogether at first?

Thanks!

Hi

You may choose to work using units or MD.I'll give some pointers instead of drawing MD.

At first
Stanley ------ 35 units
Timothy ------ 18 units

After Stanley gave 2/7 of his marbles (10 units) to Timothy, and Timothy received 16 marbles from his brother.

In the end
Stanley ------ 25 units
Timothy ------ 18 units + 10 units + 16 ------ 28 units + 16

In the end, Stanley had 5/6 as many marbles as Timothy.

Cross multiply or equalising the parts.

150 units ------ 140 units + 80
10 units ------ 80
1 unit ----- 8

In the end, Timothy ------- (28*8) + 16 ------ 240

At first, they had (35+18)*8 ------424

Good night.

Best wishes

[blueymum]

Dear all,


Would need some help for the following questions:

1. Mary had a box of beads and buttons. 4/7 were beads. Mary gave away 57 buttons. Of the beads, 5/12 of them were red, 3/5 of the remainder were blue and the rest were yellow. If there were 84 blue beads, how many buttons were left?


2. Susan had a total of 402 mangoes and pineapples. She sold 28 pineapples and 1/9 of the mangoes. The number of pineapples left became 1/4 of the number of mangoes left. how many mangoes did Susan have at first?

Thanks so much!!

[tianzhu]

blueymum:

1. Mary had a box of beads and buttons. 4/7 were beads. Mary gave away 57 buttons. Of the beads, 5/12 of them were red, 3/5 of the remainder were blue and the rest were yellow. If there were 84 blue beads, how many buttons were left?

Hi

Good Morning.

This question on remainder concept may be solved using MD or Branch Method (BM).

Please refer to an earlier solution as an example.

I did a quick check and the answer is 123 buttons.

Best wishes

http://farm8.staticflickr.com/7157/6580178853_c0e063bd36_z.jpg\">

[tianzhu]

blueymum:

2. Susan had a total of 402 mangoes and pineapples. She sold 28 pineapples and 1/9 of the mangoes. The number of pineapples left became 1/4 of the number of mangoes left. how many mangoes did Susan have at first?

Hi

You may use MD to solve this question.

I’ll give you some pointers.

Draw 9 boxes to show the number of mangoes. Colour 1 box to show the number of mangoes sold (1/9).Hence, you’ll have 8 boxes of mangoes remaining.

Draw 2 boxes to show the number of pineapples remaining (1/4 of the number of mangoes left). Add 28 pineapples sold.

11 units + 28 ------ 402
11 units ------ 374
1 unit ----- 34

Number of mangoes at first ------- 34*9 -------306

Best wishes

[YumYum]

Dear Tianzhu,


Thanks for working out the solutions for all the Qns late last nite.

I will need to go back to OnSponge for the basic concepts n run thru’ with my dd.

Enjoy the rest of the w-end.

[MathAche]

Can anybody provide the model for this problem?


John has 3 times as many stamps as Peter. When John loses 420 stamps and Peter loses 40 stamps, Peter has twice as many stamps as John. How many stamps does each of them have at first?