Q&A - P5 Math

[trytry]

mama_10:

Hi,


Need help on below question :-
Ryan, Sean and Tristan collected a total of 492 bookmarks. Ryan had the least number of bookmarks. At first, the ratio of the number of bookmarks Sean had to the ratio of bookmarks Tristan had was 3:2. After Ryan and Sean each gave away 50% of their bookmarks, Sean had 74 bookmarks more than Ryan. If the three boys had 326 bookmarks left, howmany bookmarks did Ryan have in the beginning?

Thank you.

Model
Before
R[.|.]
S[..|..][..|..][..|..]--->6u
T[..|..][..|..]--->4u

After
R[.|<-74->
S[..|..][..|--->3u
T[..|..][..|..]--->4u

326+74=400----->10u(making R 3u)
1u-->400/10=40

3u=40x3=120
After R--->120-74=46
Before R--->46x2=92

[concerned1970]

Hi, is there anyone who can help me to solve the following ques from CHIJ 2008’s SA2 paper. Ques are 7, 11, 35, 36, 40, 45 and 47. Pls do not use algebra. Ty in adv.

[MathIzzzFun]

concerned1970:

Hi, is there anyone who can help me to solve the following ques from CHIJ 2008's paper. Ques are 7, 11, 35, 36, 40, 45 and 47. Pls do not use algebra. Ty in adv.

SA1 or SA2?

You may want to try to upload the question as jpg here. Here's how you can do it:

1) open the file
2) cut out the question using snipping tool (windows 7) or you can also download \"picpick\" from the internet.
3) save as jpg and upload here

cheers.

[concerned1970]

I’m terribly sorry. I’m sucks at using pc. May I know how to convert the file to JPG? Ty.

[concerned1970]

Pls help to solve the pb sums, anyone. Thanks in adv.

1) B, R and K have 5356 stickers altogether. B has 296 more stickers than R and 4 times as many stickers as K. How many stickers does K have?

2) R dropped a basketball from a height of 110m and found that it bounced to 3/4 of the previous height for every bounce. What would be the total distance traveled by the basketball when it hit the ground the 2nd time?

3) Wendy baked some cookies and packed them into containers of 12 cookies each. If she gives 2 containers to each of her cousins, she would have 62 cookies left. If she gives 3 containers to each of her cousins, she would be short of 22 cookies. A) how many cousins does she have? B) how many cookies did she bake?

4) Mr F had a sum of money. He gave half of his money plus $570 to his wife. He gave half of the remainder plus $420 to his parents. Then he gave half of the remainder to his daughter, Abby. He also bought a dress that cost $89 for Abby. If Mr F was left with $568, how much money did he have at first?

[shawnlim88]

concerned1970:

Pls help to solve the pb sums, anyone. Thanks in adv.

1) B, R and K have 5356 stickers altogether. B has 296 more stickers than R and 4 times as many stickers as K. How many stickers does K have?

K [ ]
B [ ] [ ] [ ] [ ]
R [ ]<-296->

K has 1u
so u + 4u + (4u-296) = 5356
9u = 5356+296
= 5652
u = 5652 / 9 = 628

concerned1970:

2) R dropped a basketball from a height of 110m and found that it bounced to 3/4 of the previous height for every bounce. What would be the total distance traveled by the basketball when it hit the ground the 2nd time?

1st drop : 110
UP: 3/4 of 110 = 82.5
down same distance as up: 82.5

so distance traveled: 110 + 82.5*2 = 275m

Q3, Q4: still thinking.

[shawnlim88]

MathIzzzFun:

concerned1970:

Hi, is there anyone who can help me to solve the following ques from CHIJ 2008's paper. Ques are 7, 11, 35, 36, 40, 45 and 47. Pls do not use algebra. Ty in adv.

SA1 or SA2?

You may want to try to upload the question as jpg here. Here's how you can do it:

1) open the file
2) cut out the question using snipping tool (windows 7) or you can also download \"picpick\" from the internet.
3) save as jpg and upload here

cheers.

hi concerned1970
CHIJ 2008 SA1 or SA2??
i can cut and post the questions for you.

pls specifiy

shawnlim88

[shawnlim88]

concerned1970:

Pls help to solve the pb sums, anyone. Thanks in adv.


3) Wendy baked some cookies and packed them into containers of 12 cookies each. If she gives 2 containers to each of her cousins, she would have 62 cookies left. If she gives 3 containers to each of her cousins, she would be short of 22 cookies. A) how many cousins does she have? B) how many cookies did she bake?

i am using a method taught by my boy:

Situation 1: 2x12xC + 62
Situation 2: 3x12xC - 22
difference: 12c = 84 ( omit the + / - of the numbers, just take absolute )
so: c = 84 / 12 = 7cousins

cookies made: 2x12x7 + 62 = 230
counter check: 3x12x7 - 22 = 230

PS: if the left over is both +ve or both -ve, you need to take the difference between them.
If the left over is 1 +ve 1 -ve, then just add them togehter.

concerned1970:

4) Mr F had a sum of money. He gave half of his money plus $570 to his wife. He gave half of the remainder plus $420 to his parents. Then he gave half of the remainder to his daughter, Abby. He also bought a dress that cost $89 for Abby. If Mr F was left with $568, how much money did he have at first?

very difficult Qn. still thinking.

[shawnlim88]

concerned1970:

4) Mr F had a sum of money. He gave half of his money plus $570 to his wife. He gave half of the remainder plus $420 to his parents. Then he gave half of the remainder to his daughter, Abby. He also bought a dress that cost $89 for Abby. If Mr F was left with $568, how much money did he have at first?

<------------------------------ WIFE --------------------------->
<---------------------------------------------------------->|570|
<------------------------>|420|<---------Parent------->|
<----------->|<--Abby->|
<568>|<89>
so:
<568>|<89>
|<--Abby-->|420|
<----Parent----->|
<---------------->|570|
<------WIFE ---------->

568 + 89(dress) = 657
abby gest 657
before giving abby: 657*2 = 1314

parents get: additional 420 = 1734
before giving parents: 1734*2= 3468

wife gets additional 570 : 4038
before giving wife: 4038*2 = 8076

answer: $8076

hope it helps.
i don't think a P5 student is able to solve this under exam condition.
:stupid: :stupid: :stupid:

[CloudeeDaz]

concerned1970:

4) Mr F had a sum of money. He gave half of his money plus $570 to his wife. He gave half of the remainder plus $420 to his parents. Then he gave half of the remainder to his daughter, Abby. He also bought a dress that cost $89 for Abby. If Mr F was left with $568, how much money did he have at first?

do not know how to present in a better way
hope i dont confuse you

working backwards

Mr F left --->$89 + $568 = $657

$657 x 2= $1314
$1314 + $420 = $1734
$1734 x 2 = $3468
$3468 + $570 = $4038
$4038 x 2 = $8076 (ans)

edit : haha..ninja'd