Q&A - P5 Math

[GoopPwr]

Would be thankful for any help -


on the first day John read a book, and the ratio of pages read to the number of unread pages w 1:9, on the second day, John read another 20 pages, and the ratio became 1:7 - pages read to pages unread. What is the total number of pages of the book

Thank you

[tianzhu]

happyheart:

please help. Thank you in advance!


Q) Ali used some rectangular and square tiles to make a wall design. The rectangular tiles were sold at 3 for $12 and the square tiles were sold at 2 for $6. If he spend $546 on an equal number of rectangulars and square tiles, how many rectangular Nd square tiles dis he use altogether?

Hi

We need an equal number of rectangular and square tiles.

A common multiple of 2 and 3 is 6

Consider 1 group of 3 rectangular tiles

2 groups ------- 6 rectangular tiles --------$24

Consider 1 group of 2 square tiles

3 groups ------- 6 square tiles --------$18

A set of 6 rectangular tiles and 6 square tiles -------$42

546/42 ------- 13

There are 13 sets.

Hence 13*6*2 ------- 156

Best wishes

[tianzhu]

GoopPwr:

Would be thankful for any help -


on the first day John read a book, and the ratio of pages read to the number of unread pages w 1:9, on the second day, John read another 20 pages, and the ratio became 1:7 - pages read to pages unread. What is the total number of pages of the book

Thank you

Hi

A neat way is to use MD. Due to time constraints, I’ll work using units.

First day

Read:Unread ------- 1u:9u

Second day

Read:Unread ------- 1u + 20 :7u + 140

Compare the MD

10 units ------ 8 units + 160

2 units ------ 160

1 unit ------ 80

Total number of pages of the book ------- 10*80 ------- 800

Best wishes

[tianzhu]

pineapple tarts:

Sorry to trouble u guys again. Pls help me with this question. Thank you.


In May, the ave. nos. of participants in one pottery class was 24. In June, 5 new pottery class were added. The ave. nos. of the participants in all pottery class became 26. If there were 32 participants in each of the new pottery classes, find the total nos. of participants in all pottery classes in June.

Hi

32 – 26 ------ 6

6*5 ------ 30

26 – 24 ------- 2

Number of existing classes (May) ------- 30/2 ------ 15

Total number of classes in June ------ 20 (15+5)

Total nos. of participants in all pottery classes in June ------ 26*20 ------ 520

Best wishes

[tianzhu]

pineapple tarts:

One more...


Don and Larry had 315 stickers altogether. Don gave ¼ of his stickers to Larry. After that, Larry gave ½ of all he had to Don. In the end, Don had twice as many sticker as Larry.
(a) how many stickers did Don have at first?
(b) how many stickers did Larry have at first?

Hi

The total number of stickers stays the same.

In the end, Don had twice as many stickers as Larry.

Don ------- 2 units

Larry ------ 1 unit

3 units ------ 315

1 unit ------ 105

Don had I unit or 105 stickers before receiving 1 unit (1/2 of Larry’ share)

He had 105 stickers after giving ¼ of his share to Don

¾ -------- 105

¼ -------- 35

Hence, Don’s number of stickers@ the beginning ------- 140

Larry@first ------ 315 – 140 ------- 175

Best wishes

[tianzhu]

pineapple tarts:

Sorry sorry, last one for the day.


At 2p.m. the ratio of the nos. of girls to the nos. of boys at the library was 5:3. After 2p.m., 40 girls left the library and 40 boys entered the library and the ratio became 3:4.
(a) how many girls were there at the library at first?
(b) how many more boys were there at the library after 2p.m.?

Hi

Please confirm.

Is it 44 or 40?

Best wishes

[GoopPwr]

Ratio of one-dollar and fifty-cents coins - 2 :5 . 140 fifty-cents coins changed to one-dollar coins. In the end one-dollar coin to fifty-cents coin is 5 : 2. Find value of fifty-cent coins at the begining.


Thanks very much Tian Zhu

[GoopPwr]

Hotel Hollywood and Hotel Broadway had total of 5,200 guests. 3/4 of guest in hotel hollywood and 3/5 of guest from Broadway checked out. Hotel Broadway had 260 more guest than Hollywood. How many guest did Hotel Hollywood have at first.


Thanks for your time and any help

[tianzhu]

GoopPwr:

Hotel Hollywood and Hotel Broadway had total of 5,200 guests. 3/4 of guest in hotel hollywood and 3/5 of guest from Broadway checked out. Hotel Broadway had 260 more guest than Hollywood. How many guest did Hotel Hollywood have at first.


Thanks for your time and any help

Hi

You may work using MD or units.

In the end

Hotel Hollywood ------ 2 units (1/4 remaining, 3/4 checked out)

1/4 ------ 2 units

Hotel Broadway ------ 2 units + 260 (2/5 remaining, 3/5 checked out)

1/5 ------ 1 unit + 130

At first

Hotel Hollywood ------ 8 units

Hotel Broadway ------ 5 units + 650

13 units + 650 ------- 5200

1 unit ------ 350

Number of guests@Hotel Hollywood at first------ 8 * 350 ------ 2800

Best wishes

[tianzhu]

GoopPwr:

Ratio of one-dollar and fifty-cents coins - 2 :5 . 140 fifty-cents coins changed to one-dollar coins. In the end one-dollar coin to fifty-cents coin is 5 : 2. Find value of fifty-cent coins at the begining.

Hi

This is one possible way.

At first

one-dollar : fifty-cents ----- 2u:5u

Change

140 fifty-cents coins changed to 70 one-dollar coins

1 one-dollar : fifty-cents ----- +70:-140

In the end

1 one-dollar : fifty-cents ----- 5p:2p

2u + 70 ----- 5p

(x2)

4u + 140 ----- 10p

5u – 140 ----- 2p

(x5)

25u - 700 ------ 10p

Equalising the parts

4u + 140 ----- 25u - 700

21u ----- 840

1u ----- 40

Number of fifty-cents coins@first ------ 5*40 ------ 200

Value of fifty-cent coins at the beginning ------- $100

Best wishes