Q&A - PSLE Math

[tianzhu]

2DMommy:

In March,the total savings of Andy, Henry, Roy and Zack was $2498. In April, the savings of the four boys became equal after Andy's savings decreased by $65. Henry's savings doubled and Roy's savings increased by $129. Zack's savings remained the same. What was Roy's savings in March ?

Hi

You may use MD.

In April

Andy ------ 2 units
Henry ------ 2 units
Roy ------ 2 units
Zack ------ 2 units

In March

Andy ------ 2 units + 65
Henry ------ 1 unit
Roy ------ 2 units - 129
Zack ------ 2 units

7 units ------2498+129-65 -------- 2562
1 unit ------ 366

Roy ------ (2*366) – 129 ------ 603

Best wishes

[2DMommy]

Thank you tianzhu.


I have another question :

5 workers take 3 hour 40 mins to paint a house if every worker paints at the same rate and all start and end at the same time. If one of them leaves after painting for an hour, how long will it take the remaining workers to complete the job after the worker has left ?

[tianzhu]

2DMommy:

5 workers take 3 hour 40 mins to paint a house if every worker paints at the same rate and all start and end at the same time. If one of them leaves after painting for an hour, how long will it take the remaining workers to complete the job after the worker has left ?

Hi

Where is this question from?

You may wish to draw a simple pictorial representation.

1 worker ------ 11 units
20 mins ------- 1 unit
60 mins (1h) ------ 3 units

If one of them leaves after painting for an hour, his remaining 8 units would be divided among the other four workers.

Hence each worker ------ 10 units (8+2)

10 units ------ 200 mins

It’ll take the remaining workers another 3hr and 20 mins to complete the job.

Best wishes

[MathIzzzFun]

2DMommy:

Thank you tianzhu.


I have another question :

5 workers take 3 hour 40 mins to paint a house if every worker paints at the same rate and all start and end at the same time. If one of them leaves after painting for an hour, how long will it take the remaining workers to complete the job after the worker has left ?

Hi

another approach is to use the man-hour concept.

After working for one hour, amount of work left for each worker = 2h 40 min = 8/3 h

Total amount of work left = 5 x 8/3 man-hour = 40/3 man-hour
Amount of time taken for 4 workers to complete the job
= 40/3 /4 = 10/3h = 3h 20min

cheers.

[2DMommy]

Thank you MathIzzzFun

[lynntan15]

someone pls help. thks.

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Q1) Sally, Yiling and Ali shared a bag of beads. Sally received 3/4 of the bag of beads and 3/4 of a bead. Yiling received 3/4 of the remaining bag of beads and 3/4 of a bead. Ali received th last bead in the bag.

[tianzhu]

lynntan15:

someone pls help. thks.

-------------

Q1) Sally, Yiling and Ali shared a bag of beads. Sally received 3/4 of the bag of beads and 3/4 of a bead. Yiling received 3/4 of the remaining bag of beads and 3/4 of a bead. Ali received th last bead in the bag. ___ missing information ___

Hi

I think some information is missing from your question.

What does the question setter want the students to do?

Find the total number of beads? How many beads did Sally receive? or ......

Please refer to this similar type of question which was posted in one of the earlier posts.

Best wishes

http://farm5.staticflickr.com/4019/4713599224_8f586290c0_z.jpg\">

[tianzhu]

Hi PSLE 2012 students


This question from 2DMommy is quite an interesting one.

Best wishes

5 workers take 3 hour 40 mins to paint a house if every worker paints at the same rate and all start and end at the same time. If one of them leaves after painting for an hour, how long will it take the remaining workers to complete the job after the worker has left ?

[lynntan15]

Sorry,, here the correct Qns: -


Sally, Yiling and Ali shared a bag of beads. Sally received 3/4 of the bag of beads and 3/4 of a bead. Yiling received 3/4 of the remaining bag of beads and 3/4 of a bead. Ali received th last bead in the bag. How many beads did Sally received?
(no bead was to be divided in any way.)

[tianzhu]

lynntan15:

Sorry,, here the correct Qns: -


Sally, Yiling and Ali shared a bag of beads. Sally received 3/4 of the bag of beads and 3/4 of a bead. Yiling received 3/4 of the remaining bag of beads and 3/4 of a bead. Ali received th last bead in the bag. How many beads did Sally received?
(no bead was to be divided in any way.)

Hi

Please study the solution for the similar question.

The answer to your question is 24

1unit ----- 1+3/4 -----7/4
4 units ------7

1 part ------- 7 + 3/4
3 parts ------ 23 + 1/4

Sally ------- 23 +1/4 + 3/4 ------- 24

Best wishes

http://farm5.staticflickr.com/4019/4713599224_8f586290c0_z.jpg\">