Q&A - PSLE Math

[Angel25]

CHIJ Prelims 2011 P2 Q12


At 8.30am, Myke and Jerome set off at the same time from Town X to Town Y. At 11.00am, Myke completed his journey but Jerome had covered only 5/8 of the journey. Jerome’s speed was 54km/h slower than Myke’s.

a) Find the distance between Town X and Town Y.
b) At what time would Jerome complete his journey?

[Angel25]

Pei Chuan Public School Prelim 2011 P2 Q18


At first, Ella had $52 more than Felix. After Ella had spent 25% of her money and Felix had spent 3/5 of his, Ella had $123 more than Felix. How much money did Ella have at first?

[Angel25]

Pei Chuan 2011 Prelims P2 Q12 http://i55.tinypic.com/6ps1tw.jpg\">

[Angel25]

Pei Chuan 2011 Prelims P2 Q14

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[dingdongrc]

Is the answer to the Enry Park Math Qn 5 = 51.48 cm2?

[dingdongrc]

dingdongrc:

Is the answer to the Enry Park Math Qn 5 = 51.48 cm2?

Sorry, I meant Henry Park Prelims P2 Q10.

[MathIzzzFun]

Angel25:

Pei Chuan 2011 Prelims P2 Q14

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Hi

this was discussed in an earlier post ..

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

cheers.

[MathIzzzFun]

Angel25:

Pei Chuan 2011 Prelims P2 Q12 http://i55.tinypic.com/6ps1tw.jpg\">

Hi

Draw a diagram to show the journey - it will help to see the problem better.

Let X be the point the motorist passed the taxi. From X, the taxi travelled for 1.5h and was still 25 km away from town A.
So, distance AX (Town A to Point X) = 25 km + 90 km/h x 1.5 h = 160 km

Time taken by motorist to travel distance AX = 4h - 1.5h = 2.5h

The motorist took 4h to travel from Town A to Town B,
distance between Town A & Town B = 4/2.5 x 160 km = 256 km

cheers.

[dingdongrc]

Angel25:

Henry Park Prelim 2011 Q15.


Mr Lee packed some oranges into big boxes and apples into small boxed. Each big box contained 50 oranges and each small box contained 30 apples. After packing, there were 12 more big boxes than small boxes. Given that there were 1240 fewer apples than oranges, how many oranges were there ?

I am a rusty old woman attempting here:

Ratio of packing: Or: Ap = 5 : 3
And Or - Ap = 1240
After packing there are additional 12 x 50 = 600 oranges

Using ratio diff of 5-3 = 2, this equates to the diff of 1240-600 = 640.
2u = 640
1u = 320

Oranges initially = 5 x u +600 = 2220

I did a counter-chcek theerafter to make sure. I need some expert help to exhibit my answers more mathmathically more correctly...these are just logical workings in my brains....

[MathIzzzFun]

Angel25:

Pei Chuan Public School Prelim 2011 P2 Q18


At first, Ella had $52 more than Felix. After Ella had spent 25% of her money and Felix had spent 3/5 of his, Ella had $123 more than Felix. How much money did Ella have at first?

Hi

You can solve this using MD too.. I am using the units method here as I do not time to draw the model...

Felix = 20u
Ella = 20u + 52

Ella spent 25%, had 3/4 left --> 15u + 39
Felix spent 3/5, had 2/5 left --> 8u

So, 15u + 39 = 8u + 123, 7u = 84, 1u = 12

At first, Ella had 20u + 52 = $292

cheers.