Q&A - PSLE Math

[Despair]

Sorry for the trouble, five tough questions,


1. Mr Foo started to travel from Town P to Settlement Q on his limousine at 10 30 at an average speed of 48km/h. After taking a rest for 45 min, he continued travelling from Settlement Q to City R at an average speed that was 1.5 times his earlier average speed. He arrived at City R at 15 00. Given that the distance between Settlement Q and City R is 30 km less than the distance between Town P and Settlement Q, find the distance between Town P and City R.

[Despair]

Despair:

Sorry for the trouble, five tough questions,


1. Mr Foo started to travel from Town P to Settlement Q on his limousine at 10 30 at an average speed of 48km/h. After taking a rest for 45 min, he continued travelling from Settlement Q to City R at an average speed that was 1.5 times his earlier average speed. He arrived at City R at 15 00. Given that the distance between Settlement Q and City R is 30 km less than the distance between Town P and Settlement Q, find the distance between Town P and City R.

http://www.onsponge.com/forum/35-thinkingmathonsponge/13507-rosyth-2011-prelim-paper-mind-boggling-questions.html#13510

For the rest of the questions

[Andrew Lee]

Hi, how to solve this?

http://i54.tinypic.com/rcshzd.jpg\">

[MathIzzzFun]

Despair:

Sorry for the trouble, five tough questions,


1. Mr Foo started to travel from Town P to Settlement Q on his limousine at 10 30 at an average speed of 48km/h. After taking a rest for 45 min, he continued travelling from Settlement Q to City R at an average speed that was 1.5 times his earlier average speed. He arrived at City R at 15 00. Given that the distance between Settlement Q and City R is 30 km less than the distance between Town P and Settlement Q, find the distance between Town P and City R.

Hi

Total travelling time from P to R = 1500 - 1030 - 45min = 3h 45 min = 225 min

From Q to R, Mr Foo travelled at 48 km/h x 1.5 = 72 km/h

Add a point X after R such that XR = 30 km. Now PQ = QX and assume that Mr Foo travelled at 72km/h for the distance XR = 30km, so he will taken another 30/72 x 60 = 25 min. Total time taken from P to X = 225 min + 25 min = 250 min

Speed ratio - speed PQ : speed QX = 48 : 72 = 2 : 3
Time ratio - Time taken to travel PQ : Time to travel QX = 3u : 2u
5u = 250 min, 1u = 50 min

So, total distance from P to R
= 3u x 48 km/h + 2u x 72km/h - 30km (since we have added an arbitrary distance of 30 km)
= 3 x 50/60 x 48 + 2 x 50/60 x 72 - 30
= 210 km

cheers.

[MathIzzzFun]

Andrew Lee:

Hi, how to solve this?

http://i54.tinypic.com/rcshzd.jpg\">

Hi

please check question ...

http://i52.tinypic.com/30ug1e0.jpg\">

cheers.

[looking4Tutor]

Appreciate some help for these 2 questions -


http://i53.tinypic.com/117en84.jpg\">

TIA

[MathIzzzFun]

Despair:

Despair:

Sorry for the trouble, five tough questions,


1. Mr Foo started to travel from Town P to Settlement Q on his limousine at 10 30 at an average speed of 48km/h. After taking a rest for 45 min, he continued travelling from Settlement Q to City R at an average speed that was 1.5 times his earlier average speed. He arrived at City R at 15 00. Given that the distance between Settlement Q and City R is 30 km less than the distance between Town P and Settlement Q, find the distance between Town P and City R.

http://www.onsponge.com/forum/35-thinkingmathonsponge/13507-rosyth-2011-prelim-paper-mind-boggling-questions.html#13510

For the rest of the questions

Hi

in a rush now, I will post the diagrams later...

Q10 for Rosyth.. DE = DA, so angle DAE = angle DEA, this should make it easier to solve.

-problem sum on shaded areas with circles X,Y,Z

a) perimeter of shaded region = 1 1/3 circumference of circle.

b) shaded area = 2/3 area of circle ..draw another circle with centre at 12 o'clock from Y and passing through Y to visualize the parts.

...here are the diagrams...

http://i54.tinypic.com/svngyb.jpg\">

and the circles.. I think the calculations should be easy with this..

http://i53.tinypic.com/beezpg.jpg\">


cheers.

[Daddy]

Hi,


Afraid of ratio & fraction in the question. Very confusion. Do not know how to solve. Need help on this. Thanks…

Irene had a total of 1686 red, blu and green balloons for sale.
The ratio of the number of red balloons to the number of blue balloons was 2:3.
After Irene sold 3/4 of the blue balloons, 1/2 of the green balloons and none of the red balloons, sha had 922 balloons left.
How many blue balloons did Irene have at first?

BTW, any best method to solve most ratio and fraction questions. Thanks

[MathIzzzFun]

looking4Tutor:

Appreciate some help for these 2 questions -


http://i53.tinypic.com/117en84.jpg\">

TIA

Hi

http://i54.tinypic.com/svngyb.jpg\">

cheers.

[MathIzzzFun]

Daddy:

Hi,


Afraid of ratio & fraction in the question. Very confusion. Do not know how to solve. Need help on this. Thanks..

Irene had a total of 1686 red, blu and green balloons for sale.
The ratio of the number of red balloons to the number of blue balloons was 2:3.
After Irene sold 3/4 of the blue balloons, 1/2 of the green balloons and none of the red balloons, sha had 922 balloons left.
How many blue balloons did Irene have at first?

BTW, any best method to solve most ratio and fraction questions. Thanks

Hi

http://i51.tinypic.com/2emzm8l.jpg\">

cheers.