Q&A - PSLE Math

[raghupavithra]

John had a sum of money. On Monday, he spent 25% of his money. On Tuesday, he spent 1/3​ of his money. On Wednesday, he spent 25% of what he spent on Monday and Tuesday. If he had $39 left, how much did he have at first?



how to do this.pls help me?

[Vanilla Cake]

raghupavithra:

John had a sum of money. On Monday, he spent 25% of his money. On Tuesday, he spent 1/3​ of his money. On Wednesday, he spent 25% of what he spent on Monday and Tuesday. If he had $39 left, how much did he have at first?

Refer to Uncle tianzhu's solution.

[tianzhu]

raghupavithra:

John had a sum of money. On Monday, he spent 25% of his money. On Tuesday, he spent 1/3​ of his money. On Wednesday, he spent 25% of what he spent on Monday and Tuesday. If he had $39 left, how much did he have at first?



how to do this.pls help me?

Hi

You may use UM or MD.

Draw a bar of 48 units.

Mon ----- 12 units (25% 0f 48))

Tues ----- 16 units (1/3 of 48)

Wed -----7 (25% of 28)

Left ------ 48 -35 ------13 units

13 units ------39

1 unit ------3

48 units ------144

Best wishes

[tianzhu]

Hi VC


Please refer to your PM.

Best wishes

[tianzhu]

raghupavithra:

how solve this Express $1 as a percentage of 25-cents.


400%
25%
20%
4%

Hi

$1 is 4 times of 25 cents.

Percentage ------4/1*100 -------400%

or 100/25*100 -------400%

Best wishes

[Vanilla Cake]

P5G:

My answer for question 10 is 49.16 kg (correct to 2 decimal places).I minus 3 x 15 from the total weight since the bathroom scale shows 5 kg, which I interprete it to mean each reading will be 5 kg more.

The question does not state to round off the answer, so I correct it to 2 decimal places

http://i53.tinypic.com/29dtmki.png\">
72.6x3-15=202.8

B : A
2 : 3

C : B
4 : 5

B : A : C
10 : 15 : 8

202.8/33x8 = 49.163.... kg = 49.16 kg (2 decimal places)
Yes, this should be the correct answer.

[raghupavithra]

how to get 48

[raghupavithra]

how solve this Express $1 as a percentage of 25-cents.


400%
25%
20%
4%

Hi

$1 is 4 times of 25 cents.

Percentage ------4/1100 -------400%

or 100/25100 -------400%

Best wishes


no they put answer is 20 how i get this answer

[Hifive]

tianzhu:

Hifive:

A group of pupils calculated their average score for a Science Test. They noted that:

if anyone of them scored 13 marks more, their average score would be 90
if anyone of them scored 5 marks less, their average score would be 87

How many pupils were there in the group?

Hi

13 marks more and 5 marks less, this means a gap of 18 marks.

The difference in average mark is 3 (90-87)

18/3 ----- 6
18 marks are distributed among 6 students.

The answer is 6.

Best wishes.

Hi tianzhu

Thanks for your explanation. Have a nice day!

[mumwgals]

Hi ladies and gentlemen, please help me with this question, if possible to do this question without solving using simultaneously method. Thank you very much.


HPPS prelim paper 2 question 17,

There were 1000 students at the parade ground and indoor sport hall. 40% of the 600 students at the parade ground were girls. 60% of the students at the indoor sport hall were girls. After some students in both venues moved from one venue to the other, 30% of the students in the parade ground and 70% of the students at the indoor sport hall were girls. How many students were there in the indoor sports hall after the movement had taken place?