Q&A - PSLE Math

[tianzhu]

Michaelia0816:

Pls help with this question from my HW, I do not know how to do?


1) a car and a coach travelled from town a to town b.the coach left town a a 0648 and took 5 hours to reach town b.the car started 30 minutes later than the coach and it took 4 hours to reach town B.At what time did the car catch up with the coach?

Hi

This question has been discussed before.

Best wishes

http://farm5.staticflickr.com/4149/4847914819_b35953e42b_z.jpg\">

[Michaelia0816]

Thx!

[Michaelia0816]

But I got more question, my teacher said it found in prelim too from recent exam!

[Michaelia0816]

Help this question

Web:
http://t.co/rLfIhEi6
Find the angle of angle S and T

[nounou]

Dear Tianzhu,


\"This gives 13 units (24-6-5) -------195\" -> why???
:?: Can you please explain where does 24 come from? What is 24?

Many thanks. :thankyou: :lovesite:

tianzhu:

Chan09:

Need help on this:
A car travel from X to Y at a speed 60km/h.
A van which started moving later than car travelled from Y to X at a speed 50km/h.
They met each other after the car had travelled 3/4 of the journey.
When car reached Y, the van is still 195km away from X.
What is the total distance between X and Y?

Ans: 360km.

Can I take that in 1 hour the car will cover 10km more ...but got stuck.

Hi

Would you like to share where is this question from?

A neat way to solve this question is to use inverse ratio.

Speed of car:Speed of van -------- 60:50 -------- 6:5
Distance travelled by car: Distance travelled by van --------- 6:5

Divide the distance line into 4 parts.

The car travelled 6 units and the van travelled 5 units during the same period.

This gives 13 units (24-6-5) -------195

1 unit ------- 15

Distance between X and Y ------- 24*15 ------- 360

Best wishes

[nounou]

:thankyou: :udaman: :rahrah: :goodpost:

tianzhu:

Treelodge:

Kindly include explanation as well. Can't understand the working :gloomy: :stupid: :imdrowning: :imsorry:
Many thanks X 100000000000000 :?:
:thankyou:
:salute:

Hi

Good Morning.

My earlier response to anneshirleygilbert’s question was an attempt to break down the question for her to draw out the MD.

I’ll attempt to further break down the question into smaller parts.

Betina spent $20 on some stickers and bookmarks. She spent $4 more on the stickers than on the bookmarks.

This gives us,

Amount spent on stickers ------ 12
Amount spent on bookmarks ------- 8

Please draw the MD.

She bought 6 times as many stickers as bookmarks.

Bookmarks ------ 1 box
Stickers ------- 6 boxes

The amount spent on stickers is shown by 6 boxes.

Hence, 1 box of stickers ------- 12/6 ------- 2

The amount spent on bookmarks is shown by 1 box + an amount equal to (8 – 2).

There is an extra of 6 (8-2) because the bookmark costs 30 cents more than a sticker.

From here, we are able to calculate the number of bookmarks.

Number of bookmarks ------- 600/30 ------ 20

Therefore cost of 1 bookmark -------- 800/20 ------- 40 cents.

Best wishes

[tianzhu]

Michaelia0816:

2) A car can only travel in the east or south direction. how many different ways can the car travel from point A to point B based on the following grids?

A_____ _____ _____
|_____|_____|_____|
|_____|_____|_____| B

Sorry, can't scan the picture, too small! Dun be misunderstood it
The grids:
6 boxes with A on the top of the left while B is bottom of the right.
^
See above------------------|

Hi

If I read your question correctly, the answer is 10.

For a 2 by 2 grid, there are 6 possible routes, for a 2 by 3 grid, there are 10 routes.

I guess many students have to rely on listing of possible routings to get the answer.

In this case, it’s not too tedious.

Another way to solve it is to label the number of routings at the intersection.

Please check with your school teacher if such questions are in the syllabus.

Best wishes

[tianzhu]

Hi Treelodge


Just curious, are you a parent or PSLE student?

You seem to be asking questions based on questions posted earlier by others.

In questions on Speed, it’s really helps to start with a simple diagram.

They met each other after the car had travelled 3/4 of the journey.

Divide the distance line into 4 parts.

The car travelled 6 units and the van travelled 5 units during the same period.

Hence, 1 part ------ 6 units

4 parts ------ 24 units

This gives 13 units (24-6-5) -------195

Best wishes

[tianzhu]

Michaelia0816:

Help this question

Web:
http://t.co/rLfIhEi6
Find the angle of angle S and T

Hi

Triangle UVX is isosceles.

Hence, angle S ----- (180 – 36)/2 -------- 72

Angle WXY ------- 180 -72 ------- 108 (angle on a straight line)

Angle XYZ -------- 72 (angles between two parallel lines)

Angle t ------- 180 – 55 – 72 ------- 53

Best wishes

[Michaelia0816]

Thx, but my teacher said that she found it in psle prelim papers in recent years!!