Q&A - PSLE Math

[MathIzzzFun]

Be a mom:

http://i49.tinypic.com/16p0f7.jpg\"> Hi, Pls help on this question!!!!

Remainder --> 11 units
Original amount of money --> 11 units + $1155

Amount left = 11 units - 2 units - $175 = 9 units - $ 175
Amount left = 1/11 original amount --> 1 unit + $105
9 units - $175 = 1 unit + $ 105
1 unit --> $ 35

Amount spent on bag --> $70
original amount of money --> 11 x $35 + $1155 = $1540
... can you work out the solution from here ?

cheers.

[tianzhu]

Spongy:

Please help me in some questions. Thanks in advance!!!


1. A box contains 40 similar writing pads. The total mass of box with 3/5 of its contents is 0.88kg lighter than the box with all its contents. The mass of each writing pad is 4/5 times the mass of the box. Find the total mass of the box of writing pads. Give your answer in grams.

2. A train, 135m long travels at a constant speed of 15m/s. The train entered a tunnel which 4365m long at 12pm. Point B is the end of the tunnel.
(a) What time will it be for the entire train pass through the tunnel?
(b)What is the distance from point B to the next station if the train reaches the next station at 12.12pm.

Hi

(1)

3/5 of 40 -------- 24

16 writing pads ------- 880g

1 writing pad ------ 55g


Mass of box ------ 68.75g

The total mass of the box of writing pads -------- 68.75 + 40(55) ------- 2268.75g

(2)

Time taken to pass through tunnel ------- 4365+135/15 -------- 300s (5min)

Train passed through [email protected]

In 7min, the train covered 7*60*15 -------- 6300m

Distance from B to the next station(rear end of train@platform) ------ 6300m.

Best wishes.

[tianzhu]

Michaelia0816:

Pls help, quite urgent, cannot understand what this question saying,


http://t.co/zaxc2Izu

Hi

If it's 1/5 mark, I'd go for 1/8.

Best wishes

[paranoid]

http://i49.tinypic.com/2njc4ko.jpg\">

Killer question from Nanyang Prelim paper
Could someone help me

Thanks so much.

[MathIzzzFun]

paranoid:

http://i49.tinypic.com/2njc4ko.jpg\">

Killer question from Nanyang Prelim paper
Could someone help me

Thanks so much.

discussed at http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=7950

cheers.

[match3frog]

Please help with the following question:


A car was travelling from Town P to Town Q.

After completing 2/7 of the journey in 1/2 hour, the car passed a van travelling at a constant speed of 70km/h in the same direction.
3 hours later, the car reached Town Q but the van was still 65 km away from Town Q.

(a) Find the average speed of the car.

(b) If the van left Town P at 0810, at what time would it arrive at Town Q?

Thank you

[tianzhu]

Hi


Please refer to MathIzzzFun’s solution.

Best wishes

[Michaelia0816]

Ok!

[match3frog]

Thanks tianzhu, the question is from ds’s school worksheet. I will ask him to check the question again.


Here’s another one:

Mr Siew drove from Town X to Town Y at 60km/h. If he increased his speed by 12km/h, he would reach Town Y 1 hour earlier. Find the speed he must travel after the first 120km so that he can reach Town Y 4/5h earlier.

Thank you.

[paranoid]

MathIzzzFun:

paranoid:

http://i49.tinypic.com/2njc4ko.jpg\">

Killer question from Nanyang Prelim paper
Could someone help me

Thanks so much.

discussed at http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=7950

cheers.

Thanks for your easy-to-understand explanation. It makes the question much easier to solve.