Q&A - PSLE Math

[notfreemom]

Hi, please help me with this question.


Evergreen School spent $9065 on some tennis rackets and badmintob rackets. The ratio of the number of tennis rackets bought to the number of badminton rackets bought was 5:7. A tennis rackets costs $13.30 more than a badminton racket. The total cost of the tennis racket was 17/20 of the total cost of the badminton rackets. Find the cost of the one such tennis racket.
Thanks.

[tianzhu]

notfreemom:

Hi, please help me with this question.


Evergreen School spent $9065 on some tennis rackets and badmintob rackets. The ratio of the number of tennis rackets bought to the number of badminton rackets bought was 5:7. A tennis rackets costs $13.30 more than a badminton racket. The total cost of the tennis racket was 17/20 of the total cost of the badminton rackets. Find the cost of the one such tennis racket.
Thanks.

Hi

One neat way is to use MD.Due to time constraints, I'll give some pointers.

The total cost of the tennis racket was 17/20 of the total cost of the badminton rackets.Evergreen School spent $9065 on some tennis rackets and badminton rackets.

Hence, tennis rackets ------- 4165 and badminton rackets ------ 4900

The ratio of the number of tennis rackets bought to the number of badminton rackets bought was 5:7

7 units ------ 4900
1 unit ------ 700

4165 – (5*700) ------- 665

Number of tennis rackets ------ 665/13.3 -------50

Cost of 1 tennis racket ------ 4165/50 ------ 83.3

Best wishes

[notfreemom]

Thanks for our prompt reply. I appreciate it very much.

[Neat]

tianzhu:

Neat:

Hi morning,


Please assist on the following question:

30% of the books in a library were fiction, 25% of them were non-fiction and the rest were reference books. After 200 more fiction and non-fiction books were ordered, the percentage of the reference books in the library decreased to 40% and the number of fiction books increased by 10%. How many non-fiction books were ordered?

Thanks vm

Hi

You may use MD or UM.

FB:NFB:RB ----- 30%:25%:45% -------6u:5u:9u

RB remained unchanged.

40% ------ 9u
60% ------- 13.5u

13.5u ------- 11u + 200
1u ------ 80

Number of FB at first ------6*80 -------480
Number of FB in the end ------ 528 (10% increase)

Number of FB and NFB in the end ------13.5*80 ------1080
Number of NFB in the end ------- 1080 – 528 ------552

Number of NFB at first ------ 5*80 ------- 400
552 – 400 --------152

Number of NFB ordered ------152

Best wishes

[quote]Thanks tianzhiu :congrats: [/quote]

[Neat]

Neat:

tianzhu:

[quote=\"Neat\"]Hi morning,


Please assist on the following question:

30% of the books in a library were fiction, 25% of them were non-fiction and the rest were reference books. After 200 more fiction and non-fiction books were ordered, the percentage of the reference books in the library decreased to 40% and the number of fiction books increased by 10%. How many non-fiction books were ordered?

Thanks vm

Hi

You may use MD or UM.

FB:NFB:RB ----- 30%:25%:45% -------6u:5u:9u

RB remained unchanged.

40% ------ 9u
60% ------- 13.5u

13.5u ------- 11u + 200
1u ------ 80

Number of FB at first ------6*80 -------480
Number of FB in the end ------ 528 (10% increase)

Number of FB and NFB in the end ------13.5*80 ------1080
Number of NFB in the end ------- 1080 – 528 ------552

Number of NFB at first ------ 5*80 ------- 400
552 – 400 --------152

Number of NFB ordered ------152

Best wishes

[quote]Thanks tianzhiu :congrats: [/quote][/quote][quote]Sorry! :oops: :thankyou: [/quote]

[homeworkmummy]

mathfreak:

Superbugs:

Nan Hua CA1 P6 2011

Q14.
My salary is 1/5 more than my sister but 20% less than my brother. If our total salary is $11,100, what is my sister's salary?

If Me=100%
Brother =120%
Sister=80%
80/300x11,100=2960
but answer is $3000?
Pls assist. Tks

Actually, if Me is 100%, Sister is not 80% (this means \"Me\" had 1/4 more than Sister), but instead is 100%*5/6=83 1/3%. This is so that 1/5 of Sister added to Sister will give \"Me\".
Brother is also not 120% (this means \"Me\" had 16 2/3% less than Brother), but instead is 100%*5/4=125%. This is so that 20% of Brother subtracted from Brother will give \"Me\".

The total would be 308 1/3%, which means 83 1/3% is $3000.

Could you pls advise if this can be solved by model method. My DD was confused with the percentage method.

[tianzhu]

Hi notfreemom and Neat


You’re welcome.

Best wishes

[homeworkmummy]

I need help for another 1 Qs from Nan Hua paper.


Mrs Samy had a sum of money to spend. She spent 1/2 of her money plus $4 on a handbag. She then spent 1/2 of the remaining money plus $2 on a pair of shoes. Finally she spent 2/3 of what was left plus $1 on a skirt. She was then left with $11.
(a) How much did each item cost?
(b) How much money did she have at first?

[pixiedust]

Appreciate any help with this question :


http://i1197.photobucket.com/albums/aa424/pixie_dust8/ksp2012/mq3.jpg\">

[tianzhu]

pixiedust:

Appreciate any help with this question :


http://i1197.photobucket.com/albums/aa424/pixie_dust8/ksp2012/mq3.jpg\">

Hi

Let angle DCF be u

DCF=BCA=DEF = u

ABC + CDE = 120
Likewise, BAC+CFE =120

Add the sum of angles for the triangle ABC and parallelogram CDEF

ABC + CDE + BAC + CFE + 3u --------180+360 ------540
3u ------- 540 - 120 - 120 ------300

u -------100

Best wishes