Q&A - PSLE Math

[atutor2001]

[quote]

A man spent 1/5 of his money on clothes and a few sevenths on food. He has $152 left. How much did he spend on food?[/quote]This question is actually a prelim question from a neighbourhood school. It is very interesting because it tests the kids understanding of fractions and multiples. For those who love using model, it is the easiest way to understand.

[small]

tianzhu:

Thank you for your help.


http://farm3.static.flickr.com/2547/3984945203_a6bc525a6c_o.jpg\">

Hi Tianzhu,

Hopes this helps. I did not know if this is correct answer.

The two triangles are overlapping to each other,so we have to minus 75cm2 for one of the triangle.

http://www.postimage.org/Ts2eK_ri.jpg\">

[tianzhu]

atutor2001:

[quote]

A man spent 1/5 of his money on clothes and a few sevenths on food. He has $152 left. How much did he spend on food?

This question is actually a prelim question from a neighbourhood school. It is very interesting because it tests the kids understanding of fractions and multiples. For those who love using model, it is the easiest way to understand.[/quote]Hi
Is the answer $912?

[tianzhu]

The answer from the WS is 19:14


Best wishes

[atutor2001]

tianzhu:

quote]


Hi
Is the answer $912?

My answer is $380

[tianzhu]

atutor2001:

My answer is $380

Hi
I think you are right.
I wrongly assume the sevenths to be on the remaining sum.

Best wishes

[Muffins]

tianzhu:

Hi Muffins


When 40% more lorries from an industrial estate entered carpark P ----- how do we interpret this statement?

If the intention of the question setter is that the number of existing lorries is increased by 40%, I agree with your solution.

Best wishes

To tell you the truth, Tianzhu, I interpreted the problem exactly like you did at first! However, I think the question setter is trying to say 40% of the units of the lorries at first, 3 units, or as I put it in my working step, 15 units. If you work out the problem by multiplying the units of lorries at first by 140%, the problem would work out. By the way, the answer for the question is 564. Also, if you want a more detailed working of this problem I'd be happy to do it for you!

Wishing your child(ren) all the best for their PSLE!

[Praise]

Hi,


Can someone help to solve the following questions :-

1) There are some black and white marbles in a bag. If 20 black marbles are removed from the bag, the total number of marbles left will be 7 times the number of black marbles left. If 50 white marbles are removed from the bag, the total number of marbles left will be 5 times the number of black marbles left. How many marbles are there in the bag?

2) 65% of the animals on a farm were cows and the rest were goats. When 240 more cows and goats were added to the farm, the percentage of cows increased by 20% and the number of goats doubled. How many goats were there on the farm at first.

3) The ratio of the number of pencils to the number of erasers in a box was 2 : 3. When 42 pencils were added and 15 erasers were removed, the ratio of the number of pencils to erasers became 3:4. How many erasers were there left in the box?

[tianzhu]

Hi Muffins


Thank you for your offer.I understand your solution.

You have assumed that the unit of measures for both ratios is the same.

I appreciate your well wishes.May all PSLE kids be abundantly blessed with fruitful results.

Best wishes

[atutor2001]

tianzhu:

I wrongly assume the sevenths to be on the remaining sum.

Best wishes

Thanks for confirming. I find it amazing that such questions are set for P6