Q&A - PSLE Math

[kiasuaunt]

tianzhu:

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.

[Essential]

Hi Tianzhu, not sure this question any one asked before . Please kindly help us. The sum of 6 numbers is 624 . When a 7th number is added . The average of the numbers increases by 2. When a 8th number is added, the average of the 8 numbers increases by 2 again . Find the 8th number.

[tianzhu]

Essential:

Hi Tianzhu, not sure this question any one asked before . Please kindly help us. The sum of 6 numbers is 624 . When a 7th number is added . The average of the numbers increases by 2. When a 8th number is added, the average of the 8 numbers increases by 2 again . Find the 8th number.

Hi

For 6 numbers

Average ------ 624/6 ------ 104

For 7 numbers

Average ------ 106

Total ------ 106*7 ------- 742

For 8 numbers

Average ------ 108

Total ------ 108*8 ------- 864

The 8th number ------- 864 – 742 ------- 122

Best wishes

[Essential]

Hi anyone can help this question? A car left town A at 0800 and travelled to Town B at an average speed at 60 km/h. at the same time , a lorry left town B for Town A. At 11 30 , the car and the lorry were 85 km apart after passing each other earlier . If the car arrived at Town B at 1300 , at what time would the lorry arrived at Town A?

[Essential]

Thank u Tianzhu you are super fast . May I know are u a tutor?

[tianzhu]

Essential:

Hi anyone can help this question? A car left town A at 0800 and travelled to Town B at an average speed at 60 km/h. at the same time , a lorry left town B for Town A. At 11 30 , the car and the lorry were 85 km apart after passing each other earlier . If the car arrived at Town B at 1300 , at what time would the lorry arrived at Town A?

Hi

It’s useful to have a pictorial representation for Speed questions.

I’ll just provide some pointers.

Draw a bar, and label A and B at both ends.

At 1130, the car is at point C and the lorry is at point D.(D is nearer to A).

From 0800 to 1130, the car covered 60*3.5 ----- 210 km (A to C)

From 1130 to 1300, the car covered 60*1.5 ----- 90 km (C to B)

Distance (B to D) travelled by lorry from 0800 to 1130 ------ 90 + 85 ------ 175 km

From here, lorry’s speed ------ 175/3.5 ------- 50 km/h

From point D to A, the lorry covered (210 – 85) which is 125 km

Time taken by lorry ------125/50 ------ 2.5 h

From 1130h, add 2.5h, this gives 1400 h

Best wishes

[tianzhu]

Essential:

Thank u Tianzhu you are super fast . May I know are u a tutor?

Hi

No

Best wishes

[Robertpattinsonidle]

qsn.Find the number and letter that best fits in the following pattern. 6O,8C,4T,?


someone please help me! thanks in advance.
pls help and reply ASAP

[Robertpattinsonidle]

A,B,C,D,E,F are letters that represent different digits such that BC is a 2 digit no. & the


decimal form of A/BC is 0.DEFDEFDEF… What is the largest possible value of BC?

this question needs a lot of thought. someone help me!!!please!!!

[kiasuaunt]

tianzhu:

kiasuaunt:

2. There are 2 bags of jelly beans labelled A and B. In bag A, there are 470 red jelly beans and 480 green jelly beans. In bag B, there are 350 red jelly beans and 200 green jelly beans. Some red and green jelly beans from bag B are transferred to bag A. As a result, 60 percent of the jelly beans in bag A and 20 percent of those in bag B are red. How many red and how many green jelly beans are transferred from bag B to bag A?

Hi

This question touches on SE.

You may use MD, UP or use letters of the alphabet to show the variables.

Due to time constraints, I’ll just provide some pointers using UP.

At first

Bag A

R:G ------ 470:480

Bag B

R:G ------ 350:200

After the transfer

Bag A

R:G ------ 3u:2u

Bag B

R:G ------ 1p:4p

3u + 1p ------- 820 (470 + 350)

2u + 4p ------ 680 (480 + 200)

12u + 4p ------ 3280

10u ------ 2600

1u ------ 260

Bag A

R:G ------ 3u:2u ------- 780:520

Red ----- 780 – 470 ------ 310

Green ----- 520 - 480 ------ 40

Best wishes

:thankyou: for the clear explanations.