Q&A - P5 Math

[MathIzzzFun]

MommyDearest:

MathIzzzFun:

[quote=\"MommyDearest\"]Could somebody please help me with this qtn too ?


Hotel Hollywood and Hotel Broadway had a total of 5200 guests.
After 3/4 (three quarter) of the guests in Hotel Hollywood and 3/5 (three fifths) of the guests in Hotel Broadway checked out, Hotel Broadway had 260 more guests than Hotel Hollywood. How many guests did Hotel Hollywood have at first ?

TIA !!

Hi

after guests check out,
Hotel Hollywood --> 2 units
Hotel Broadway --> 2 units + 260 = 2 x (1 unit + 130)

At first,
Hotel Hollywood --> 8 units
Hotel Broadway --> 5 units + 650

Total --> 13 units + 650 = 5200, 1 unit --> 350
At first, Hotel Hollywood --> 2800

cheers.

Thanks MathsIzzzFun for your swift reply !! Appreciate it

Just a few things to clarify:

The 8 units that you use for the “at first” scenario was obtained after you make the end ratio the same, is it correct ? ie. you multiply Hollywood’s start/change/end ratios by 2 ? Resulting in the 2 units for Hollywood after guests check out ?

Please correct me if I’m wrong.

I understanding the rest of the working.[/quote]Hi

the reason is that the fraction remaining is 2/5 for Broadway --> so, choose a multiple of 2 ie 2 units which is the smallest.

cheers.

[sherlynDD]

tianzhu:

YumYum:

2. The ratio of the number of ten cent to twenty cent stamps in an album was 3:4. 50 ten-cent stamps were taken out, exchanged for twenty cent stamps of the same value and put back into the album. The ratio became 1:5. Find the total value of all the stamps in the album at first.

Hi

One possible way

At first

ten cents stamps: twenty cent stamps ------ 3u:4u

50 ten-cent stamps were taken out, exchanged for twenty cent stamps of the same value and put back into the album.

50 ten-cent stamps ------- 25 twenty cent stamps

Change

ten cents stamps: twenty cent stamps ------ -50:+25

In the end

ten cents stamps: twenty cent stamps ------ 1p:5p

Equalise the parts.

3u – 50 ------ 1p
(x5)
15u – 250 ------ 5p

4u + 25 ------ 5p

15u – 250 ------- 4u + 25

11u ------ 275

1u ------- 25

Total value of all the stamps in the album at first

ten cents stamps: twenty cent stamps ------ (3*25)*10cents : (4*25)*20cents ------- $27.50

Best wishes

Hi,

Here maybe another way.
As from the statement that the exchange was done with same value, we could transform the ratios to reflect value. Therefore, we can have

Before change,
The ratio of number:
# of Ten-cent stamps : #of Twenty-cent stamps = 3:4

Well, the ratio of the values is
Value of Ten-cent stamps : Value of Twenty-cent stamps = 3:8
Total value: 3+8=11

After change,
The ratio of number:
# of Ten-cent stamps : #of Twenty-cent stamps = 1:5
However,
the ratio of the values became,
Value of Ten-cent stamps : Value of Twenty-cent stamps = 1:10

We can see the the tatol value kept same, (1+10) =11
the value of Ten-cent changes: 3 -> 1, 2unit less in value
2u = 500 cent -> u = 250 cent

Therefore, the initial value was 11unit = 11*250 cent = $27.50

Cheers,

[MommyDearest]

MommyDearest:

:?:

Hi, Can someone please help me out on this question ?

(Source: NANYANG CA2 2011 Paper 2)
NY Primary School organised a 2-Day Charity Funfair. Admission tickets were sold to every visitor at a cost of $40. On the first day, 120 more children visited the funfair than adults. The number of children on the second day was 25% more than the number of children on the first day. The number of adults on the second day was 5% less than the number of adults on the first day. There were a total of 2570 people at the funfair on the second day.

(a) Find the number of adults at the funfair on the first day.

(b) What was the total sum of money collected from the sale of the admission tickets for both days ?

Thanks in advance !! :please:

Can anyone please help ?
TIA !!

[MommyDearest]

MathIzzzFun:

MommyDearest:

:?:

Hi, Can someone please help me out on this question ?

(Source: NANYANG CA2 2011 Paper 2)
NY Primary School organised a 2-Day Charity Funfair. Admission tickets were sold to every visitor at a cost of $40. On the first day, 120 more children visited the funfair than adults. The number of children on the second day was 25% more than the number of children on the first day. The number of adults on the second day was 5% less than the number of adults on the first day. There were a total of 2570 people at the funfair on the second day.

(a) Find the number of adults at the funfair on the first day.

(b) What was the total sum of money collected from the sale of the admission tickets for both days ?

Thanks in advance !! :please:

Hi

Day 1,
Adults --> 20 units ---- 5% --> 1 unit
Children --> 20 units + 120 ---- 25% --> 5 units + 30

Day 2,
Adults --> 19 units
Children --> 25 units + 150
total Adults + Children --> 44 units + 150 = 2570
1unit --> 55 ... can you continue from here ?

cheers.

Thanks MathIzzzFun! Overlooked your reply from this morning.

[YumYum]

Hi, can anyone pls help with this qn:


David has 10% fewer cookies Ian but 40% more cookies than Rauf. If they have a total of 890 cookies, how many cookies does Ian have? Thks

[PiggyLalala]

YumYum:

Hi, can anyone pls help with this qn:


David has 10% fewer cookies Ian but 40% more cookies than Rauf. If they have a total of 890 cookies, how many cookies does Ian have? Thks

Rauf: 100%
David: 140%
Ian: 100/90 x 140% = 1400/9%

Total = 100 + 140 + 1400/9 % --- 890 cookies
3560/9 % ---- 890 cookies
1400/9 % ----890 x 1400/3560 =350 cookies

[YumYum]

Hi PiggyLalala, many thanks!

[happyheart]

Hi,

Can someone explain & illustrate this questions with model?

Q) Mr. Chua has a class of less than 40 pupils. He gave all the pupils in his class some jellybeans. If he gave 5 jellybeans to each pupil, he would have 2 jellybeans left. If he gave 4 jellybeans to each pupil, he would have 38 jellybeans left.

a) How many pupils were there in his class?
?) How many jellybeans did Mr Chua have?

Thanks.

[tianzhu]

happyheart:

Hi,

Can someone explain & illustrate this questions with model?

Q) Mr. Chua has a class of less than 40 pupils. He gave all the pupils in his class some jellybeans. If he gave 5 jellybeans to each pupil, he would have 2 jellybeans left. If he gave 4 jellybeans to each pupil, he would have 38 jellybeans left.

a) How many pupils were there in his class?
?) How many jellybeans did Mr Chua have?

Thanks.

Hi

This is a typical question under “Gap and Difference” or “Excess and Shortage”. Different books labelled them differently.

There are a few approaches, while a visual representation may help students to see better in the beginning, it’s usually not necessary once they become more familiar with the logic behind the solution.

Try to see it from this angle,to give each pupil one less jellybean (5-4), Mr Chua would have 36 (38-2) more jellybeans left.

Number of pupils ------- 36/1 ------- 36

Number of jellybeans -------- 36*5 + 2 ------- 182

Alternatively (36*4) + 38 ------- 182

Other approaches include “Multiple method” which involves listing of multiples. Another possible way is to work with units.

Here’s a solution for a similar type of question. Hope you’ll find it useful.

Best wishes

http://farm7.staticflickr.com/6176/6193593312_fe5ffb9348_z.jpg\">

[happyheart]

tianzhu:

happyheart:

Hi,

Can someone explain & illustrate this questions with model?

Q) Mr. Chua has a class of less than 40 pupils. He gave all the pupils in his class some jellybeans. If he gave 5 jellybeans to each pupil, he would have 2 jellybeans left. If he gave 4 jellybeans to each pupil, he would have 38 jellybeans left.

a) How many pupils were there in his class?
?) How many jellybeans did Mr Chua have?

Thanks.

Hi

This is a typical question under “Gap and Difference” or “Excess and Shortage”. Different books labelled them differently.

There are a few approaches, while a visual representation may help students to see better in the beginning, it’s usually not necessary once they become more familiar with the logic behind the solution.

Try to see it from this angle,to give each pupil one less jellybean (5-4), Mr Chua would have 36 (38-2) more jellybeans left.

Number of pupils ------- 36/1 ------- 36

Number of jellybeans -------- 36*5 + 2 ------- 182

Alternatively (36*4) + 38 ------- 182

Other approaches include “Multiple method” which involves listing of multiples. Another possible way is to work with units.

Here’s a solution for a similar type of question. Hope you’ll find it useful.

Best wishes

http://farm7.staticflickr.com/6176/6193593312_fe5ffb9348_z.jpg\">

This is great! Tianzhu. Thank you so much:)