Q&A - PSLE Math

[tianzhu]

anneshirleygilbert:

Hello Tianzhu,

I've not followed this thread for several days..... until now.

But, I have some trouble following your steps in this question. Can you help?

Hi anne

I apologise for the hiccup.

This question looks pretty similar to the one posted in the P5 thread, I did a cut and paste of my earlier solution in the P5 thread without realising that part (a) was different.

The earlier response was for this question in the P5 thread.

Both shops , ABC and XYZ , offered a 15% discount for the same type of mattress. If Mr. Muthu were to buy from shop XYZ, he would have paid $38.25 less than the discounted price in Shop ABC.

a) What was the difference in the original price of the mattress between the two shops?

b) The original price of the mattress in Shop ABC was $1510. What was the minimum percentage discount it must offer so that the discounted price in Shop ABC would be lower than the discounted price in shop XYZ? Give your answer correct to the nearest percent.

For Essential's question, please refer to below.

For (a)

15% ------- 38.25

100% ------- 255 (discounted price in ABC)

For (b)

In this case, we are working based on the given original price of $1510

Discounted price in ABC -------- 1510*0.85 ------ 1283.50

Discounted price in XYZ -------- 1283.50 – 38.25 ------- 1245.25

1510 – 1425.25 ------- 264.75

264.75/1510*100% ------- 18%

Best wishes

[Ready2WORK]

MathIzzzFun:

Ready2WORK:

If the perimeter of each isosceles triangle is 34, then each side must be 11 one-third, so y would then be 11 one third times 4, which is then 45 one-third. Explain? :scratchhead:

for isosceles triangle, only 2 sides are of same length ie the base (in this case = y/4) is not of the same length of the other 2 sides.

cheers.

Oh yeah, thanks. :clubmyself: :clubmyself: :booboo:

[Ready2WORK]

MathIzzzFun:

Ready2WORK:

I was thinking about that point too, but you can't be sure that it rearranges into a exact half-rugby. So that was probably not the solution.

for this question, tianzhu interpretation is correct. If the \"mid-point thickness\" of the \"leaf\" is equal to half radius, the 3 outer circles will not be touching each other, using trigo/pythgoras theorem.

http://i47.tinypic.com/90t2cz.png\">

cheers.

And I got the solution. Thanks for pointing out mistake.

[paranoid]

tianzhu:

paranoid:

Hmm Tianzhu, how can it be proven that the shaded part A can be re-arranged to form a half-rugby like you mentioned? Someone else provided a different answer.

Hi

When dealing with composite figures, one of the more efficient ways is to work with familiar shapes. Students should be pretty well versed in familiar shapes.

The answer to your question is 224 sq cm.

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8462/8024994319_c3bfa77fea_z.jpg\">

Thanks so much :thankyou: :udaman:

[anneshirleygilbert]

Is there something wrong with this question? I can’t solve it by SE?


Stall A and Stall B had some apples and oranges. 5/7 of Stall A’s fruits and 3/4 of Stall B’s fruits were oranges. Stall A had 34 more apples than Stall B. If Stall A had 245 more fruits than Stall B, how many fruits did the two stalls have altogether?

This question is from one of the practice papers given by my daughter’s math teacher… unfortunately, wasn’t marked as there wasn’t enough time.

Please help. TIA

[MathIzzzFun]

anneshirleygilbert:

Is there something wrong with this question? I can't solve it by SE?


Stall A and Stall B had some apples and oranges. 5/7 of Stall A's fruits and 3/4 of Stall B's fruits were oranges. Stall A had 34 more apples than Stall B. If Stall A had 245 more fruits than Stall B, how many fruits did the two stalls have altogether?

This question is from one of the practice papers given by my daughter's math teacher.... unfortunately, wasn't marked as there wasn't enough time.

Please help. TIA

I think the last sentence should be \"If Stall B had 245 more fruits than Stall A, how many fruits did the two stalls have altogether?

Stall B's apples --> 1/4 of fruits = 2/8 of fruits --> 2 units,
total number of fruits in Stall B --> 8 units
Stall A's apples --> 2 units + 34 = 2 x (1 unit +17),
total number of fruits in Stall A --> 7 x ( 1unit + 17) = 7 units + 119
Stall B had 245 more fruits than Stall A

7 units + 119 + 245 = 8 units
1 unit --> 364
I believe you can continue from here... got to go for my final session with my P6s...

cheers..

[anneshirleygilbert]

Thank you, MathIzzzFun. If the last sentence is changed as you have suggested, then the question is do-able by SE. Thanks a lot.

[Robertpattinsonidle]

3. Two cars race around a circular track at constant speeds starting at the same point. If they travel in opposite direction, then they meet every 30 seconds. If they travel in the same direction, then they meet every 2 min. If the track is 1800m long, what is the speed of each car? ans: 22.7m/s and 37.5m/s.

[tianzhu]

Robertpattinsonidle:

3. Two cars race around a circular track at constant speeds starting at the same point. If they travel in opposite direction, then they meet every 30 seconds. If they travel in the same direction, then they meet every 2 min. If the track is 1800m long, what is the speed of each car? ans: 22.7m/s and 37.5m/s.

Hi

This question has been discussed on page 833.

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=8320

Best wishes

[Shimmer]

Hi can someone help my dd ?


At a rugby match 1/4 of the spectators bought 1 pack of snack each. 3/5 of the remaining spectators bought 2 packs of snacks each. The remaining spectators bought 4 packs of snacks each. Given that all spectators bought 3854 pack of snacks , how many spectators ate there ?