Q&A - PSLE Math

[Mary Joy]

MathIzzzFun:

Mary Joy:

Please help to solve this questions...



3)During the school holidays,Chris read 312 pages of a book at first.He read the remaining pages in 20 days,with the same number of pages each day.During these 20 days,he read 1/12 of the book in 6 days.How many pages of the book did he read in the 6 days?

1/12 = 6/72
6 days --> 6/72 book
1 day --> 1/72 book
20 days --> 20/72 book
1-20/72 = 52/72

52/72 book --> 312 pages
1/72 book --> 6 pages

6 days --> 6/72 book --> 36 pages

cheers.

Thanks a lot MathizzFun

[timtamfan]

Hi, I suspect these questions may have been answered elsewhere already. Anway, I’ve asked my DD for help. I wouldn’t be able to do them myself ha ha.


1) If you share 1/3 of the candies (all the lollipops) with ? boys so they each have 1/9 of the candies, there are 3 boys as 1/3 / 1/9 = 3.
If you share 2/3 of the candies (the remainder) with ? girls so they each have 1/6 of the candies, there are 4 girls as 2/3 = 4/6>

2) Take A as Adam’s original number of beads.
(70-10)/ 2=1/3 A - 1/5 A
30\t = 2/15 A
A\t = 225
Adam had 225 beads at first

3) He can read 1/12 /6 = 1/ 72 of the book in a day and 20/ 72 (5/ 18) of the book in the 20 days.
1 - 5/ 18\t = 13/18 of the book
\t\t→ 312 pages
1\t\t→ 432 pages in the book
432 x 1/12\t→ 36
Chris read 36 pages in the 6 days

[sing_xiangxiang]

Anybody can help to solve n explain below qn?

At statio A, the ratio of the number of children to the number of adults on a train was 4:5. At the next station, 12 children alighted and 10 adults boarded the train. The ratio of the number of children to the number of adults on the train then became 7:10. How many children were on the train at first?

[MathIzzzFun]

sing_xiangxiang:

Anybody can help to solve n explain below qn?

At statio A, the ratio of the number of children to the number of adults on a train was 4:5. At the next station, 12 children alighted and 10 adults boarded the train. The ratio of the number of children to the number of adults on the train then became 7:10. How many children were on the train at first?

this was discussed in an earlier post (pg 639)... http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&p=772802&hilit=12+children+alighted#p772802

cheers.

[oceanh2o]

Please help me in this question:


Jenny spent 1/5 of her money and additional $4 on some books. She then spent 3/4 of the remaining money and additional $9 on some magazines . Given that she was left with $36, how much money did Jenny have at first ?

Thanks !

[MathIzzzFun]

oceanh2o:

Please help me in this question:


Jenny spent 1/5 of her money and additional $4 on some books. She then spent 3/4 of the remaining money and additional $9 on some magazines . Given that she was left with $36, how much money did Jenny have at first ?

Thanks !

work backwards...

$9+$36 --> 1/4 of remaining money
so, 1/4 of remaining money --> $45
remaining money --> $45 x 4 = $ 180

$180 + $4 --> 4/5 of money
so, 4/5 of money --> $184
Total amount of money Jenny had at first --> $ 184/4 x 5 = $230

alternatively, you can also use model.. from which the total amount of money at first --> $(1+9+36) x 5 = $230

cheers.

[Mary Joy]

Pls help me to solve this question…


1.At a theme park,each adult ticket cost $60 per day,while each child ticket cost $45 per day. On Saturday,the number of adult tickets sold was 90 fewer than the number of child tickets.On Sunday,the number of adult tickets sold decreased by 25%,while the number of child tickets sold increased by 20%.If a total of 576 tickets were sold on Sunday,how much money was collected on Saturday?

This question is taken from Nanyang Primary School, First continual examination 2012, Primary 6 Mathematics paper 2,Question 11

[jieheng]

Mary Joy:

Pls help me to solve this question....


1.At a theme park,each adult ticket cost $60 per day,while each child ticket cost $45 per day. On Saturday,the number of adult tickets sold was 90 fewer than the number of child tickets.On Sunday,the number of adult tickets sold decreased by 25%,while the number of child tickets sold increased by 20%.If a total of 576 tickets were sold on Sunday,how much money was collected on Saturday?

This question is taken from Nanyang Primary School, First continual examination 2012, Primary 6 Mathematics paper 2,Question 11

Sat
A 100u
C 100u + 90

Sun
A 100u - 25u = 75u
C 100u + 90 + 20u + 18 = 120u + 108


75u + 120u + 108 --> 576
195u --> 468
1u --> 2.4


Sat
A 100u --> 100*2.4 = 240
C 100u + 90 --> 100*2.4 + 90 = 330

The money collected on Saturday = 240*$60 + 330*$45 = $29250 (Ans)

[ozora]

need some help in these question.

Jean had some stamps. She gave 1/3 of her stamps plus 6 more. she gave Liz 1/3 of her remaining stamps plus 4 more. If Jean finally had half as many stamps as Liz, how many stamps did Kay receive? my answer is 15.
Besides model drawing, how to use unitary method to solve?
is it similiar to http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=8620?

[MathIzzzFun]

ozora:

need some help in these question.

Jean had some stamps. She gave Kay 1/3 of her stamps plus 6 more. she gave Liz 1/3 of her remaining stamps plus 4 more. If Jean finally had half as many stamps as Liz, how many stamps did Kay receive? my answer is 15.
Besides model drawing, how to use unitary method to solve?
is it similiar to http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=8620?

\"Kay\" was missing in the question - I have inserted as shown in blue above.

Jean --> 9 units
Kay --> 3 units + 6
Remainder --> 6 units - 6

Liz --> 2 units - 2 + 4 = 2 units + 2
Jean --> 4 units -4 - 4 = 4 units - 8
Jean had half as many as Liz
8 units - 16 = 2 units + 2
6 units --> 18, 1 unit --> 3

Kay --> 15
cheers.