Q&A - P5 Math
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GoopPwr:
HiWould 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
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 -
pineapple tarts:
HiSorry 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.
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 -
pineapple tarts:
HiOne 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?
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 -
pineapple tarts:
HiSorry 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.?
Please confirm.
Is it 44 or 40?
Best wishes -
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 -
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 -
GoopPwr:
HiHotel 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
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 -
GoopPwr:
HiRatio 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.
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 -
tianzhu:
Hipineapple 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.?
Please confirm.
Is it 44 or 40?
Best wishes
Dear Tianzhu, it's 4O leh. -
pineapple tarts:
Hi
Dear Tianzhu, it's 4O leh.
Where is this question from?
If it’s 40, you’ll end up having decimals.
If it’s 44, the answers are
First
140 boys and 84 girls
Final
96 boys and 128 girls
Best wishes