Q&A - PSLE Math

[MathIzzzFun]

Treelodge:

Hi, my girl did the Q with a different method but she is struck somewhere. We cannot figure out why and how. :?: Kindly help.


:thankyou: :thankyou: :thankyou:

MathIzzzFun:

Hi

using MD..

http://i49.tinypic.com/14w8ytt.png\">

cheers.

Hi
which method did she use ? this question can also be solved using the cross multiply or unit & part method.

(**my original post was incorrect, I have amended the post)

cheers.

[ozora]

.[/quote]Thanks but does the 2ndpart suppose to assist in answering the first part of answer.[/quote]


Hi,

Yes, students usually use the 2nd part to help answer the first part.

For the first part, when you deal with percentage change, and area (or volume), you can use the original numbers (9 and 5), or you can use your own numbers (10 and 10, which is slightly easier)

Whichever set of numbers you use, you should get the answer as 25%, for the first part.

We normally encourage students to use 2 methods, when they have the time:
One method to get the answer
Another method to check the answer.

For the second part, when you deal with perimeter, you must use the numbers (9 and 5) given in the question.
Breadth drop from 5 to 4 (drop of 20%)
Length increase from 9 to 11.25 (increase of 25%)

Old perimeter is 9 + 9 + 5 + 5 = 28
New perimeter is 11.25 + 11.25 + 4 + 4 = 30.5

Can you work on the second part from here?

Hope this helps.

Cheers


speedmaths.com


.[/quote]
thanks alot for the guide.

[tianzhu]

Michaelia0816:

Tianzhu, I dun understand this Q,


Ken was climbing a flight of stair. While standing on a step, Ken realized that there were twice as many steps above he was step on,as there were below him. After ascending 8 more steps, he noticed that they were as many steps below him as they were above him. How many steps were there in the flight of stairs?

Hi girl

Good Morning.

I observe you’ve been posting quite a number of questions in this forum, just wondering if you have a tuition teacher.

Where is this Ken’s question from? It’s an interesting one.

I did a quick check with MD and the answer is 49.

I suggest you try out the question on your own; going through the process is an important part of getting the answer.

If it still bothers, I’ll do some sketch and send it to you.

Ah, you’ve still not let me know what CBS papers are.

Best wishes

[anneshirleygilbert]

Can someone please help with this question?


Mr Lim has some kittens, white mice and birds in his pet shop. There are thrice as many birds as white mice. If these pets have 92 heads and 266 legs altogether, how many kittens are there in the shop?

TIA
Anne

[tianzhu]

anneshirleygilbert:

Can someone please help with this question?


Mr Lim has some kittens, white mice and birds in his pet shop. There are thrice as many birds as white mice. If these pets have 92 heads and 266 legs altogether, how many kittens are there in the shop?

TIA
Anne

Hi

Good Morning.

This is a typical “Counting heads and legs” type of question. It is trickier because of additional animal.

First, lump mice and kittens as one group because they have 4 legs. We want to find out the number of birds.

Suppose all were 4 legged animals.

92*4 ------- 368

368 – 266 ------ 102

Number of birds -------- 102/2 --------- 51

There are thrice as many birds as white mice.

Number of white mice -------- 51/3 -------- 17

Number of kittens -------- 92 – 51 - 17 -------- 24

Best wishes

[anneshirleygilbert]

Oh, thank you, tianzhu. How simple you’ve made it! Just lump kittens and mice together!!! Appreciate your help very much.


Anne

[Michaelia0816]

Ken answer:

Tianzhu—49
Michaelia0816—24

I cannot understand why.

[ruohoo97]

Sam and Tom walked from town A to town B at the same time. Sam was faster than Tom by 4km/h. When Sam reached town B, he immediately walked back to town A. On the way back, he met Tom who was 10 km away from town B. What was Sam’s speed?


Can someone help with this question? Thanks a lot.

[tianzhu]

ruohoo97:

Sam and Tom walked from town A to town B at the same time. Sam was faster than Tom by 4km/h. When Sam reached town B, he immediately walked back to town A. On the way back, he met Tom who was 10 km away from town B. What was Sam's speed?


Can someone help with this question? Thanks a lot.

Hi

Where is this question from?

Please check if there is missing information such as how long Sam took to walk from A to B.

A logical answer would be Sam ----- 10 km/h and Tom ------- 6 km/h.

Best wishes

[niza6666.028774hotmail.028774com]

Hi I need help on this speed question too. Thanks for helping.

Mr and Mrs Leong left their house at the same time but travel in opposite directions. Mr Leong travelled towards Bedok while Mrs Leong headed for Kallang. Mrs Leong drove at a speed which was 10km/h slower than Mr Leong. 30 minutes later, when Mr Leong reached Bedok, they were 95km apart. How far did Mrs Leong travel when Mr Leong reached Bedok?