Q&A - PSLE Math

[shurley197323]

Hi, can someone help on these 2 RGS 2011 prelim questions No 17 & 18.

No 18: Beaker A & Beaker B contain some water. If 46.5ml of water is drained out from beaker A, the volume of the water in beaker A will be 60% that of the water in beaker B.
If 35.2ml of water is drained out from beaker B, the volume of the water in beaker B will be 85% that of the water in beaker A.
What is the total volume of water in beaker A & beaker B ?

[MathIzzzFun]

shurley197323:

Hi, can someone help on these 2 RGS 2011 prelim questions No 17 & 18.

No 18: Beaker A & Beaker B contain some water. If 46.5ml of water is drained out from beaker A, the volume of the water in beaker A will be 60% that of the water in beaker B.
If 35.2ml of water is drained out from beaker B, the volume of the water in beaker B will be 85% that of the water in beaker A.
What is the total volume of water in beaker A & beaker B ?

Q17- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=6840

Q18- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&p=787503&hilit=Beaker+A#p787503

cheers.

[Shimmer]

Hi, need help on this question.


Thanks in advance.

Loges and Paul shared a packet of sweets equally. Loges packed the number of sweets he had equally into 3 pkts. Paul packed the numbers of sweets he had equally into 4 pkts. There were a total of 77 sweets in 2 pkts of sweets from Loges and 1 pkt of sweets from Paul. Find the total number of sweets in the original packet of sweet.

[kiasuaunt]

kiasuaunt:

tianzhu:

[quote=\"kiasuaunt\"]
3. There were 544 brownies and cupcakes for sale at a bakery. All the brownies at a bakery cost $488 more than all the cupcakes. After 4/5 of the brownies and 1/4 of the cupcakes were sold, there were twice as many brownies as cupcakes left. Each brownie cost 80 cents less than each cupcake. How much did each brownie cost ?

Hi

Please help to confirm.

Is it 488 or 448?

Brownies ------ 480*1.2 ------ 576

Cupcakes ------ 64*2 ------ 128

Difference ------- 448

Best wishes

Hi - yes, it's $448 - sorry.

:thankyou: for the solutions - will try to digest them now and teach my dd later. We've been keeping u very busy. Thanks again for your time and effort.[/quote]Hi - when u hv the time, can u show the working pls ? Thank you.

[shurley197323]

MathIzzzFun:

shurley197323:

Hi, can someone help on these 2 RGS 2011 prelim questions No 17 & 18.

No 18: Beaker A & Beaker B contain some water. If 46.5ml of water is drained out from beaker A, the volume of the water in beaker A will be 60% that of the water in beaker B.
If 35.2ml of water is drained out from beaker B, the volume of the water in beaker B will be 85% that of the water in beaker A.
What is the total volume of water in beaker A & beaker B ?

Q17- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=6840

Q18- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&p=787503&hilit=Beaker+A#p787503

cheers.

Ok. Thanks a lot. :salute:

[MathIzzzFun]

Shimmer:

Hi, need help on this question.


Thanks in advance.

Loges and Paul shared a packet of sweets equally. Loges packed the number of sweets he had equally into 3 pkts. Paul packed the numbers of sweets he had equally into 4 pkts. There were a total of 77 sweets in 2 pkts of sweets from Loges and 1 pkt of sweets from Paul. Find the total number of sweets in the original packet of sweet.

Hi

Number of sweets each had --> 12 units
1 pkt of sweets from Paul --> 3 units
1 pkt of sweets from Loges --> 4 units

2 pkts of sweets from Loges + 1 pkt of sweets from Paul
= 8 units + 3 units = 11 units

11 units --> 77 sweets
1 unit --> 7 sweets
Original pkt of sweets --> 12 units x 2 = 24 units = 24 x 7 = 168 sweets.

cheers.

[nounou]

Can someone please explain this Q? Is there a formula to find out ?

Why it is 2 x 2 x 2 x 2 x 3 x 7 x 9 but not any other set of numbers? :?:
:thankyou: :thankyou:

sleepyqueen:

Michaelia0816:

4) Mrs Wong gave birth to 4 children in 4 consecutive years. Today, she discovered that the product of the ages, in years, of the 4 children is 3024. How old are her 4 children now?

I know the answer, it should be 6,7,8,9 but am I suppose to add the ages together to get the final answer?

3024 = 2 x 2 x 2 x 2 x 3 x 7 x 9

from here we can see 2x2x2 = 8, 2x3 = 6, 7, 9
hence ages of the kids are 6,7,8,9

[niza6666.028774hotmail.028774com]

Hi, I need help on this question. I manage to get a). Pls help. Thank you.

Machine A and B each printed a fix number of newspapers per hour. Machine B started printing earlier at a rate of 75 copies per hour. After Machine B had printed for 10 hours, Machine A had printed 340 copies. After Machine B had printed for 16 hours, Machine A had printed 886 copies.
a) How many copies of newspapers did Machine A print per hour?
b) How long would Machine B have worked when both machines have printed a total of 2750copies?

[tianzhu]

mn:

Hi, I need help on this question. I manage to get a). Pls help. Thank you.

Machine A and B each printed a fix number of newspapers per hour. Machine B started printing earlier at a rate of 75 copies per hour. After Machine B had printed for 10 hours, Machine A had printed 340 copies. After Machine B had printed for 16 hours, Machine A had printed 886 copies.
a) How many copies of newspapers did Machine A print per hour?
b) How long would Machine B have worked when both machines have printed a total of 2750copies?

Hi

From (a),Number of copies printed by A ----- 91

Number of copies printed by A and B----- 91+75 ------166

Number of copies printed by A and B in 16h ----- 886 + (75*16) ------ 2086

2750 – 2086 ------ 664

664/166 ------- 4

Number of hours by B ------- 16 + 4 ------ 20

Best wishes

[niza6666.028774hotmail.028774com]

Tianzhu, thank you so much for the fast response.