Q&A - PSLE Math

[nounou]

Please help to solve this Q. RGS prelim 2012 Q14. :yikes: :?: :imdrowning:

:thankyou: :thankyou: :thankyou:

http://i46.tinypic.com/op8bk5.jpg\">

[tianzhu]

Treelodge:

Hi Tianzhu, can you please explain the following?

146 – (1+2) ------143 (71 and 72)
Why – (1+2)? Why -? Why 1? Why +2?

Hi

The numbers on one side of a sheet adds up to 146.

1 and 2 refers to photo number 1 and photo number 2.

Photo number 71 and 72 are also on the same side of the sheet as photo 1 and 2.

143 ------ 71 + 72 (consecutive numbers)

Best wishes

[kiasuaunt]

:thankyou: charsen.

[MathIzzzFun]

Treelodge:

Please help to solve this Q. RGS prelim 2012 Q14. :yikes: :?: :imdrowning:

:thankyou: :thankyou: :thankyou:

http://i46.tinypic.com/op8bk5.jpg\">

Case 1:
Saw into same number of pieces, Log A : Log B -> 1.2 : 0.9 = 4 : 3 -> 32u : 24u
Length of Log A -> 32u
Length of Log B -> 24u + 0.9m

Case 2:
Saw into same number of pieces, Log A : Log B -> 1.6 : 1.25 = 32u : 25u
Length of Log A -> 32u
Length of Log B -> 25u + 0.6m

Length of Log B is same in both cases :
24u + 0.9 m = 25u + 0.6m
1u -> 0.3m

Length of Log A -> 32 x 0.3 m = 9.6m

cheers.

[nounou]

You are so efficient! Many thanks! :rahrah: :boogie: :lovesite: :thankyou: :thankyou: :thankyou: :udaman:

MathIzzzFun:

Treelodge:

Please help to solve this Q. RGS prelim 2012 Q14. :yikes: :?: :imdrowning:
:thankyou: :thankyou: :thankyou:

http://i46.tinypic.com/op8bk5.jpg\">

Case 1:
Saw into same number of pieces, Log A : Log B -> 1.2 : 0.9 = 4 : 3 -> 32u : 24u
Length of Log A -> 32u
Length of Log B -> 24u + 0.9m

Case 2:
Saw into same number of pieces, Log A : Log B -> 1.6 : 1.25 = 32u : 25u
Length of Log A -> 32u
Length of Log B -> 25u + 0.6m

Length of Log B is same in both cases :
24u + 0.9 m = 25u + 0.6m
1u -> 0.3m

Length of Log A -> 32 x 0.3 m = 9.6m

cheers.

:thankyou:

[Clairifina]

:thankyou:

[Zhu99]

zanen:

Zhu99:

[quote=\"zanen\"]hello. can someone help me? please help me...both my tuition teachers refuse to...:( some boys sat in a circle. 41 fruit tarts were passed around the boys. alan happened to receive the first and last fruit tarts he received a total of 6fruit tarts. how many boys are there?

41 - 1 = 40 --- Disregard the 1st fruit tart Alan received

6 - 1 = 5 --- Number of rounds

40/5 = 8 --- No. of boys

There are 8 boys.

Alan --- 1st, 9th, 17th, 25th, 33th, 41st

may you explain to me why must disregard the lst one by alan?[/quote]
Compare this 0, 8th, 16th, 24th, 32nd and 40th with 1st, 9th, 17th, 25th, 33th, 41st. So instead of 1, we should start with 0.

[kiasuaunt]

Hi - unable to post the pic frm RGS Prelim 2011 #14b - appreciate if someone can help solve the question. Thank you.

[Zhu99]

Shimmer:

1)In a online quiz,30 points are awarded for every correct answer. 10 points are deduct for every wrong answer. Alex has 2570 points for answering 103 questions.

How many questions did Alex answer ??? again?

30 x 103 = 3090 --- if 103 Qs answered correctly

3090 - 2570 = 520 --- Marks to be reduced

30 + 10 = 40 --- Marks reduced (lost) by converting 1 correct answer to 1 wrong answer

520/40 = 13 --- No. of Qs answered wrongly

103 - 13 = 90 --- No. of Qs answered correctly

90 x 30 - 10 x 13 = 2570 --- Check and confirm correct

Shimmer:

2)A stall sold 3 kinds of juice. Coconut are at $3,Sugar Cane cost$2 and Guava cost $1.The number of juice sold for 3 data??days?? is in a ratio of 3:6:11,find the average cost each bottle sold during 3 days .?

3 x 3 + 2 x 6 + 1 x 11 = 32

3 + 6 + 11 = 20

32/20 = 1.60

The average cost of each bottle was $1.60.

Shimmer:

3)Owen made 100 sandwich for $100.Chicken are sold for $5 each, fish are sold for $2 and plain are sold for $0.10.How many sandwich did she ??? for each flavor ?

Assume she sold 70 plain sandwich --- 70 x 0.10 = $73 [We need to make an intelligent guess. We may start with 80 ---- but will not get whole number for chicken and fish sandwiches]

100 - 7 = $93

100 - 70 = 30 --- No. of chicken and fish sandwich

30 x 2 = $60 --- if 30 fish sandwich

93 - 60 = $33 --- Amt short

5 - 2 = $3 --- Amt increase if convert 1 fish sandwich to 1 chicken sandwich

33/3 = 11 --- No. of chicken sandwich

30 - 11 = 19 --- No. of fish sandwich

(70 x 0.10) + (19 x 2)+ (11 x 5) = $100 [Check and confirm correct]

70 + 19 + 11 = 100 sandwich [Check and confirm correct]

She sold 70 plain, 19 fish and 11 chicken sandwiches.

Shimmer:

4) A fruit seller had two box of fruits. Each box had mangoes and pears.
The ratio of mangoes tO pear in bOx ??A?? was 5:4. In box B the number of pear was 2/5 of mangoes. The seller transferred half of the pears in A to B.In the end the fruits in A become 105 and the ratio of mangoes to Pear ??? in B or total magoes to total pear??? is 7:4.
A) How many pears were transferred frome A to B?
B)How many fruits are in B in the end?

Box A --- M : P = 5 : 4 ---- 9 u
Box B --- M : P = 5 : 2 ---- 7 p

9 - 2 = 7 u ---> 105
1 u ---> 105/7 = 15

5 p
2 u ---> 15 x 2 = 30

a) 30 pears were transferred from A to B.

b) Information given incomplete / not clear ....?

[kiasuaunt]

MathIzzzFun:

AJH:

Hi. I nd help with this ques.


Brendan and Raidah saved $6475.60 altogether. 2/5 of Brendan's savings was $341.50 more than 1/5 of Raidah's savings. How much more money than Brendan did Raidah save?

Can't seem to get the ans - $1020.20. Thank you.

1/5 of Raidah's savings --> 2 units,
Raidah's savings --> 10 units
2/5 of Brendan's savings --> 2 units + $341.50 = 2 x (1 unit + $170.75)
Brendah's savings --> 5 units + $853.75

Total --> 15 units + $853.75 = $6475.60
5 units --> $1873.95

Raidah's savings MINUS Brendan's savings
= 5 units - $853.75
= $1873.95 - $853.75 = $1020.20

cheers.

Hi - sorry for being so slow :scratchhead: is it possible to explain by MD? Thank you.