Q&A - PSLE Math

[tianzhu]

mn:

Hi I need help on this speed question too. Thanks for helping.

Mr and Mrs Leong left their house at the same time but travel in opposite directions. Mr Leong travelled towards Bedok while Mrs Leong headed for Kallang. Mrs Leong drove at a speed which was 10km/h slower than Mr Leong. 30 minutes later, when Mr Leong reached Bedok, they were 95km apart. How far did Mrs Leong travel when Mr Leong reached Bedok?

Hi

As in any Speed question, start with a simple diagram.

In 1h, Mrs Leong covered 10 km less than Mr Leong.

In 30 minutes, Mrs Leong covered 5km less than Mr Leong.

1unit (Mrs Leong) + 1 unit + 5 (Mr Leong) ------ 95

1 unit ------- 45

Mrs Leong travelled 45 km

Best wishes

[ms_lim]

Can you help with this question?


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[tianzhu]

ms_lim:

Can you help with this question?


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Hi

This question has been discussed before.

Hope this helps.

Best wishes

http://farm5.staticflickr.com/4087/5038193821_f4be6c6c88_z.jpg\">

[concern_mum]

Hi all, pls help me with below questions.


1. A sculpture made of 4 different metals( Gold, bronze, iron and tin) weighed 60kg. the gold and bronze together accounted for 2/3 of its mass. The gold and tin comprised 3/4 of its mass. The gold and iron together weighed 36kg. find the mass of tin used.

2.
Tim, Shah and Raj had 216 book marks altogether. At first, Time gave 24 book marks to Shah. Then Shah gave 9 book marks to Raj. After that, Raj gave 17 book marks to Tim. The total number of book marks that Shah and Raj have now is half of what Tim has. The number of book marks that Shah has now is 3/5 of the number of book marks that Raj has. How many book marks did Time and Raj have altogether.

3.
Xiu Li has $34 in her piggy bank. There was a mixture of 20cents and 50cents coins. There were 5 more 50cents coins thatn 20cents coins in her piggy bank. How many 20cents coins are there in her piggy bank?

[tianzhu]

concern_mum:

Xiu Li has $34 in her piggy bank. There was a mixture of 20cents and 50cents coins. There were 5 more 50cents coins thatn 20cents coins in her piggy bank. How many 20cents coins are there in her piggy bank?

Hi

5*50 --------- 250

3400 – 250 ------- 3150

20+50 ------- 70

3150/70 --------- 45(number of 20 cents coins)

Best wishes

[Shimmer]

Hi Tianzhu


Need your help !

Isaac read a book. 1st day he read 2/5 of it unread. 2nd day he read another 24 page of the book . In the end he read was 5/9the pages did not read. If he finish the rest in 4 days. What was the average number he read for the
Rest of the book?

A rectangle tank was empty at first. Tap A was turned at a rate of 6 litres per min. After 2 min, B drain water at 2liters per min. Both tap turned off after 6 min after Zb was turned on. The tank was 28 cm in height and hold56 litres find the height of water level in tank when both tank turn off.


If a director get two designers work together Work will be completed in 6 days. If A work alone it wil completed in 10 days. He hired A to work on it for a few days and remaining B will do it.How many days A must spend so that it is done in 12 1/2 days?

[ruohoo97]

tianzhu:

ruohoo97:

Sam and Tom walked from town A to town B at the same time. Sam was faster than Tom by 4km/h. When Sam reached town B, he immediately walked back to town A. On the way back, he met Tom who was 10 km away from town B. What was Sam's speed?


Can someone help with this question? Thanks a lot.

Hi

Where is this question from?

Please check if there is missing information such as how long Sam took to walk from A to B.

A logical answer would be Sam ----- 10 km/h and Tom ------- 6 km/h.

Best wishes

It is from my kid's school paper, I also wonder whether there is mistake in question :?

[Neat]

oops.. computation error... correction in red

vanilla --> 72
chocolate --> 138

cheers.[/quote]

Thanks MathIzzzFun :thankyou:

[Neat]

o..in that case, I think the original question is likely about money instead of toys...I have changed the toys to $$ below....


Mr Samad had some money. He spent 20% of the money on Monday. He spent $27 on Tuesday. On Wednesday he spent 10% of the remaining money. After that he found that the money he had left was $1 more than 1/2 the original amount he had. How much money did he have at first ?

Original amount --> 10u
Spent on Monday --> 2u, Left --> 8u
Spent on Tuesday --> $27, Left --> 8u - $27
Spent on Wednesday --> 0.8u - $2.70, Left --> 7.2u - 24.30

So, 7.2u - $24.3 = 5u + $1
1u --> 11.5
Original amount --> 10 x $11.5 = $115

cheers.[/quote]

Thanks MathIzzzFun :thankyou:

[the shadowed snake]

Michaelia0816:

Ken answer:

Tianzhu---49
Michaelia0816---24

I cannot understand why.

Hi, I did this Q and I got 48. Is this the ans?