Q&A - PSLE Math

[tianzhu]

Michaelia0816:

3. 2 candles of the equal length are lit at the same time. One candle took 5 hours to burn out and the other 2.5 hour. After how long will the length of the faster burning candle be 4/7 of the slower burning one?

Hi

This question is crafted is such a way that it’s not too tedious to solve it in a visual manner.

Just do some colourings and the answer appears right before you.

Hope this helps.

Best wishes

http://farm8.staticflickr.com/7125/7459133158_1dbef96a77_z.jpg\">

[AJH]

MathIzzzFun:

AJH:

Hi -


Q. Jane and May share a box of beads. If Jane were to give 25% of her share to May, Jane would have half of May's final share. If Jane were to give 16 beads to May, Jane would have 54 fewer beads than May. If they were to pack all their beads into boxes of 25 each, what is the least number of boxes required to pack all of them?

Thank you.

Hi

You can see the solution quite easily with MD... I will use units to save time.

If Jane were to give 16 beads to May, Jane would have 54 beads fewer than May
After:
Jane --> 4 units
May --> 4 units + 54
At first:
Jane -->4 units + 16
May --> 4 units + 38

If Jane were to give 25% of her share to May, Jane would have half of May's final share.
1/4 of Jane's share --> 1 unit + 4
After:
Jane --> 3 units + 12
May --> 5 units + 42 = 2 x (3 units+12)
5 units + 42 = 6 units + 24
1 unit --> 18

Number of beads each had:
Jane --> 4 x 18 + 16 = 88
May --> 4 x 18 + 38 = 110
..I believe you can carry on from here..

cheers.

:thankyou: If u hv the time can u show me the MD.

[peggy]

Please assist with this.


Eugene, Freddy and George had some playing cards. Freddy had 200 more playing cards than Eugene. George had 3/4 the number of cards Freddy had. After George lost 1/6 of his cards to Eugene, he had 320 fewer cards than Eugene. What was the ratio of the number of cards Eugene had to the number of cards Freddy had to the number of cards George had in the end ?

many thanks…

[tianzhu]

peggy:

Please assist with this.


Eugene, Freddy and George had some playing cards. Freddy had 200 more playing cards than Eugene. George had 3/4 the number of cards Freddy had. After George lost 1/6 of his cards to Eugene, he had 320 fewer cards than Eugene. What was the ratio of the number of cards Eugene had to the number of cards Freddy had to the number of cards George had in the end ?

many thanks..

Hi

The question has been discussed before.

Consider this at the start.

Eugene ------ 8 units
Freddy ------ 8 units + 200
George ------ 6 units + 150

In the end

Eugene ------ 9 units + 25 ------ 970
Freddy ------ 8 units + 200 ------ 1040
George ------ 5 units + 125 ------ 650

9 units + 25 ------- 5 units + 125 +320
1 unit ------- 105

The ratio ------- 97:104:65

Best wishes

[peggy]

Tianzhu,


Much appreciated.

[Michaelia0816]

Hi Tianzhu! Thx and … I came straight to the point, can you help me with 3 question?


Here I go:
1)5 trained workers take 20 days to paint a room. 8 untrained workers can do the same task in 20 days. How long would a team of 4 trained workers and 4 untrained workers take to finish the same task?

2) 9 fewer students in the lower primany than the upper primany competed in the story telling this year. 2/3 of all those whol competed were boys. 3/7 of the lower primany participant were girls.1/4 of the participants in the upper primany were girls. How many boys took part in the competition

3) A box contained 50-cent coins, 20-cent coins and 10-cent coins in the ratio 3:2:1. 75% of the 50-cent coins were taken out and replaced by the same number of 10- cent coins. Then, 180 20-cent coins were taken out and replaced by the same number of 10-cent coins. In the end, the ratio of the number of 50- cent,20-cent and 10-cent coins became 3:4:17.
(a) What was the total number of coins taken out?
(b) Find the total value of coins taken out.

[tianzhu]

Hi


Hope this helps.

Best wishes

http://farm8.staticflickr.com/7246/7459644570_6087607dbd_z.jpg\">

[tianzhu]

peggy:

Tianzhu,


Much appreciated.

Hi

You're welcome.

Best wishes

[AJH]

tianzhu:

Hi


Hope this helps.

Best wishes

http://farm8.staticflickr.com/7246/7459644570_6087607dbd_z.jpg\">

:thankyou: very much.

[tianzhu]

AJH:

:thankyou: very much.

Hi

You're welcome.

Best wishes