Q&A - PSLE Math

[jessielu]

Need help on below question:


A dictionary cost $11 more than a book.  The book cost $45 more than a magazine.  Mr lee paid a total of $252 for 6 pieces of each item.  What is the cost of a book?

Appreciate the steps to solve this

[imacsg]

Hi Tian Zhu,

Why is it 24 x 4 ? I could not see the pattern. Can u help to show me the pattern? Thanks

[tianzhu]

imacsg:

Hi Tian Zhu,

Why is it 24 x 4 ? I could not see the pattern. Can u help to show me the pattern? Thanks

Hi

First number, second number ------ multiply by 2 ------ gives Third number, Fourth number

4*2 ------ 8
6*2 ------ 12

Third number, Fourth number ------ multiply by 3 ------ gives Fifth number, Sixth number

8*3 ------ 24
12* 3------ 36

Fifth number, Sixth number ------ multiply by 4 ------ gives Seventh number, Eighth number

24*4 ------ 96
36* 4------ 144

If you continue

96*5 ------- 480

Best wishes

[imacsg]

Thanks.


Never think of it.

[tianzhu]

jessielu:

Need help on below question:


A dictionary cost $11 more than a book.  The book cost $45 more than a magazine.  Mr lee paid a total of $252 for 6 pieces of each item.  What is the cost of a book?

Appreciate the steps to solve this

Hi

6 pieces of each item ----- these means 6 dictionaries, 6 books and 6 magazines.

(45*6) is already more than 252?

Please check your question with your source?

Best wishes

[YumYum]

Hi, can someone pls help with this Qn:


In a hall, 40% of the pupils are boys. After 10 girls left the hall, the percentage of girls decreased to 55%. How many boys are there in the hall?

Thanks!

[tianzhu]

YumYum:

Hi, can someone pls help with this Qn:


In a hall, 40% of the pupils are boys. After 10 girls left the hall, the percentage of girls decreased to 55%. How many boys are there in the hall?

Thanks!

Hi

The number of boys remained the same before and after.

At first
Boys : Girls -------- 2:3 (40%:60%) ------ 18:27

In the end
Boys : Girls -------- 9:11 (45%:55%) ------- 18:22

Make the units for boys the same

5 units ------- 10
1 unit ------ 2

Number of boys -------18*2 -------36

Best wishes

[portal]

1)I have this question to ask.A faulty weighing scale showed a reading of 0.3kg when nothing was placed on it. A box which contained 18 identical magazines was placed on the weighing scale, After 2/9 of the magazines were removed from the box, the weighing scale showed a reading of 7.82kg. The mass of each magazine was 60% the mass of the box. What is the mass of the box? Give your answer in grams. :?:

[portal]

Hope someone can help

[portal]

2)I have another question to ask.


3/4 of the fruits are apples and the rest are oranges.5/6 of the apples and 210 oranges were sold.The number of fruits left is 1/5 of the total.How many fruits were sold? :?: