Q&A - PSLE Math

[HoSayLiao]

Can someone help with this question?


Ali has $300. He lost 1/3 of it and ends up with $200. To have the $300 again, he needs to win $100 which is ½ of the $200. 1/3 is known as the Losing Fraction (LF) and ½ is known as the Winning Fraction (WF). ½ times 1/3 = 1/6. 1/6 is the product of the LF and WF, known as the PLW. Find the LF and the WF if the PLW is 81/400.

[Hifive]

Hi


Need help with this question:

A motorist sets off from Town A for Town B.
If he travels at 60km/hr, he will reach Town B at 9.30am.
If he travels at 80km/hr, he will reach Town B at 8.45am
How far apart is Town A and Town B ?

Thanks in advance!

[carebear]

Hifive:

Hi


Need help with this question:

A motorist sets off from Town A for Town B.
If he travels at 60km/hr, he will reach Town B at 9.30am.
If he travels at 80km/hr, he will reach Town B at 8.45am
How far apart is Town A and Town B ?

Thanks in advance!

I only how to solve this question with algebra.

Let x be the distance between A and B.

If the motorist travels at the faster speed, he will take 45 minutes or 3/4h faster to reach B.

Time taken in hours to reach B if he travels at 60km/h is x/60
Time taken in hours to reach B if he travels at 80km/h is x/80

x/60 = x/80 +3/4

x= 180 km

Distance between Town A and Town B is 180 km.

[bobsg01]

:nailbite:


Another P6 math problem.

Thanks in advance for any help given.

http://i51.tinypic.com/34ii74m.jpg\">

[carebear]

bobsg01:

:nailbite:


Another P6 math problem.

Thanks in advance for any help given.

http://i51.tinypic.com/34ii74m.jpg\">

a) 24 km
b) 13.5 km/h

http://www.flickr.com/photos/63342911@N03/5770283724/
http://www.flickr.com/photos/63342911@N03/5770284336/

[bobsg01]

Thank you carebear. :rahrah:

[Hifive]

carebear:

Hifive:

Hi


Need help with this question:

A motorist sets off from Town A for Town B.
If he travels at 60km/hr, he will reach Town B at 9.30am.
If he travels at 80km/hr, he will reach Town B at 8.45am
How far apart is Town A and Town B ?

Thanks in advance!

I only how to solve this question with algebra.

Let x be the distance between A and B.

If the motorist travels at the faster speed, he will take 45 minutes or 3/4h faster to reach B.

Time taken in hours to reach B if he travels at 60km/h is x/60
Time taken in hours to reach B if he travels at 80km/h is x/80

x/60 = x/80 +3/4

x= 180 km

Distance between Town A and Town B is 180 km.

Hi carebear

Thanks for your solution.

[bobsg01]

:stupid:


P6 Math problem again.

Thanks in advance for the help provided.

http://i55.tinypic.com/jqnf60.jpg\">

[MDAJP]

bobsg01:

:stupid:


P6 Math problem again.

Thanks in advance for the help provided.

http://i55.tinypic.com/jqnf60.jpg\">

Hi,

I just saw this question because I have been absent for a long time. I think this is a trick question - note that they are only asking for the perimeter, and not the area. Therefore, one only needs to add up the perimeters of the two sectors:

Perimeter of the shaded area
= 1/4 X 2 X pi X 4 + 8 + 1/2 X 2 X pi X 3 + 6

[MDAJP]

Hifive:

Hi


Need help with this question:

A motorist sets off from Town A for Town B.
If he travels at 60km/hr, he will reach Town B at 9.30am.
If he travels at 80km/hr, he will reach Town B at 8.45am
How far apart is Town A and Town B ?

Thanks in advance!

Hi Hifive,

Another way of solving this question is to make use of ratios.
The ratio of first speed to second speed is 3:4.
As the distance remains constant, time taken, which is inversly proportional to speed, will return a ratio of 4:3.
The difference in time taken is 45min.
4 parts - 3 parts = 1 part.
Hence, time taken when the speed is 60 km/h is 4 (parts)X 45 min = 3 h. Therefore, the distance is 3 X 60 = 180 km.