Q&A - PSLE Math

[doraemo]

Thank you very much , Ender !!!

[ninjamathtv]

please help :

1) The ratio of the number of marbles May, Teddy and Sam had was 3:5:2. During a game, May lost half of her marbles to Teddy. Teddy lost 20 marbles to Sam who then had 3 times the number of marbles May had at the end of the game.
a) What was the percentage increase in the number of marbles Sam had at the end of the game?
b) How many marbles did Teddy have at the end of the game?

This question seems confusing, but once you draw bar models, it becomes easy to understand. This video shows a step by step solution using bar models.

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[sushi88]

2) At a fun-raising event, 60% of the people were male and the rest were female. 20% of the female left the event in the afternoon.
In the evening, after 33 male and 35 female left the event, 75% of the people at the event were male.
a) What percentage of the people left the event in the afternoon?
b) How many people were there at the start of the fun raising event?

(a) M : F
----6u: 4u
0.2x4u = 0.8u
0.8u/10u X 100 = 8%

(b) M : F
6u-33 : 3.2u-35 (where 3.2u=4u-0.8u)

6u-33 = 0.75[6y-33+3.2u-35]
6u-33 = 0.75[9.2u -68]
6u-33 = 6.9u - 51
0.9u = 18
u= 20

Hence people at the start of event is 10u = 10 x 20 = 200

[KimNYou]

Hi Parents,


There is an easy trick to teach your child when it comes to word problems. You can ask them to draw brackets for each sentence. This because most children cannot comprehend long wordy text. By breaking down into parts, they will be able to comprehend the content better.

We hope it helps!

[ninjamathtv]

Need some guide on the following questions

Thanks

Using the bar model method to solve this question. Watch the step by step video below:

[/youtube]

[forestcadee]

Hi, I would like to confirm which will be the answer if the question ask
"how many boys and girls are there in the class?"

1) Give the answer for boys and girls separately.

OR

2) Give the answer in total.

Thanks.

[speedmaths.com]

Hi, I would like to confirm which will be the answer if the question ask
"how many boys and girls are there in the class?"

1) Give the answer for boys and girls separately.

OR

2) Give the answer in total.

Thanks.

Sh be
2) Total.

[deon629]

Pls help. Thanks.

Faith has 2 tanks, A and B of different capacities. If tank A is filled by a tap at a rate of 3 litres per minute and tank B is filled by a tap at a rate of 5 litres per minute, when tank A is completely filled, 5 litres of water flowed out from tank B.

If tank A is filled by a tap at a rate of 4 litres per minute and tank B is filled by a tap at a rate of 3 litres per minute, when tank A is completely filled, tank B is only half-filled. What is the capacity of tank B?

[sushi88]

Pls help. Thanks.

Faith has 2 tanks, A and B of different capacities. If tank A is filled by a tap at a rate of 3 litres per minute and tank B is filled by a tap at a rate of 5 litres per minute, when tank A is completely filled, 5 litres of water flowed out from tank B.

If tank A is filled by a tap at a rate of 4 litres per minute and tank B is filled by a tap at a rate of 3 litres per minute, when tank A is completely filled, tank B is only half-filled. What is the capacity of tank B?

-----------Tank A vol-----Tank B vol
Case 1-------3u-----------5(u-1)
Case 2-------4p-----------3p x2

3u=4p => p=3/4u
5 (u-1) = 3p x 2
5u - 5 = 3(3/4u) x 2
10u - 10 = 9u
u = 10

Tank B vol = 5(10-1) = 45 litres

[deon629]

Pls help. Thanks.

Faith has 2 tanks, A and B of different capacities. If tank A is filled by a tap at a rate of 3 litres per minute and tank B is filled by a tap at a rate of 5 litres per minute, when tank A is completely filled, 5 litres of water flowed out from tank B.

If tank A is filled by a tap at a rate of 4 litres per minute and tank B is filled by a tap at a rate of 3 litres per minute, when tank A is completely filled, tank B is only half-filled. What is the capacity of tank B?

-----------Tank A vol-----Tank B vol
Case 1-------3u-----------5(u-1)
Case 2-------4p-----------3p x2

3u=4p => p=3/4u


5 (u-1) = 3p x 2
5u - 5 = 3(3/4u) x 2
10u - 10 = 9u
u = 10

Tank B vol = 5(10-1) = 45 litres