Tutor MathsGuru: Ask me for your burning Maths questions!

[Brenda10]

Hifive:

Hi everyone


Need help with the following questions:
Source : Nan Hua SA2 2009 Paper 2 - P5

1. Gretel has $6.80. This amount of money was just enough to buy 6 oranges and 10 pears. Instead, she bought 10 oranges and 6 pears and had $0.80 left. Find the cost of 1 orange.

Thanks in advance.

Hi Hifive

Did this question (Q11.)before but we get the answer of $0.30 which is differnet from the answer key ($0.2) provided.

Here was dd working:

6o + 10p + 10o + 6p = $12.80
16o + 16p = $12.80
1o + 1p = $0.80 (find out 1 set)

10o + 6p = $6.00
(6 sets of 1o + 1p )+ 4o = $6.00
6 * $0.8 + 4o = $6.00
$4.8 + 4o = $6.00
4o = $6.00 - $4.80
4o = $1.20
1o = $0.30

Appreciate help to verify is the answer of $0.30 correct.

Thank you

[Brenda10]

Hifive:

Hi everyone


Need help with the following questions:
Source : Nan Hua SA2 2009 Paper 2 - P5

2. The ratio of the number of Faye's balls to the number of Ian's ball was 1:5. Then their father gave Ian 12 more balls and Faye 5 more balls. The ratio of the number of Faye's balls to the number of Ian's balls became 1:4. How many more balls did Ian have than Faye in the end?

Thanks in advance.

Q13. DD working:


F:I
1:5
+5 +12
1:4


4u = 20
5u = 12
1u = 8

I = 5 * 8 + 12
= 52

F = 1* 8 + 5
= 13

52 - 13 = 39

Hence Ian has 39 balls more than Faye in the end.

Do the checking: 13:52 = 1:4

Thank you

[Hifive]

Hi Brenda


Thanks for your help.

For question 1, ds also got $0.30.

For question 2, can you pls explain how to get 4u = 20 ?

Thanks!

[Muffins]

Hi hifive, she used cross-multiplication.


F : I
1 : 5
+5 +12
1 : 4

She multiplied the 4 at the end, to the (1 unit + 5) in the beginning. That is how she got 4u = 20

She used it again to get 5 units = 12 :

1 X (5 units + 12) = 5u + 12

Hope I helped!

[Hifive]

Hi Muffins


Got it! Thanks for your explanation.

[Brenda10]

Hifive:

Hi Muffins


Got it! Thanks for your explanation.

Hi Hifive

Just back and see your message.


Glad that Muffins's already help to provide the explanation.


Cheers

[Almighty]

Hi Dharma Sir,

Can u please help me out with this problem?

Town A and Town B are 12 km apart. At 10 a.m., Tom and Harry travelled towards each other from Town A and Town B respectively. Tom walked at a speed of 20 m/min for 2 minutes after every 10 minutes of running at 165 m/min. Harry took a 4 minutes rest after each 15 minutes of running at 165 m/min.What time did they meet each other? [2 marks]\t\t\t\t\t\t
Forum Answer:
Tom\t\t\t\t\t
 Distance (m)\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
      1650     40          1650       40           1650        40    330\t\t\t\t\t
|-----------|------|--------------|------|---------------|------|------|--------?\t\t\t\t\t
0            10     12                 22     24                 34     36    38\t\t\t\t\t
Time (min)\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
Harry\t\t\t\t\t
165 x 15 = 2475 m\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
Distance (m)\t\t\t\t\t
           2475                  0                2475                    0\t\t\t\t\t
|----------------------|--------|----------------------|------------|---------?\t\t\t\t\t
0                         15          19                          34               38\t\t\t\t\t
Time (min)\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
1650 x 3 + 40 x 3 + 330 = 5400 m\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
2475 x 2 = 4950 m\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
5400 + 4950 = 10350 m\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
12000 - 10350 = 1650 m\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
1650 /(165+165) = 5 min\t\t\t\t\t
\t\t\t\t\t
\t\t\t\t\t
38 + 5 = 43 min\t\t\t\t\t
\t\t\t\t\t
               43 min \t\t\t\t\t
   |--------------------|\t\t\t\t\t
10 am                10.43 am\t\t\t\t\t
\t\t\t\t\t
It was 10.43 a.m

Can i combine the time like this and approach this problem.?
Tom Walking: ///////////////// ///////// Harry - running
1 min --- 20 m /////////////////////////// 1 min --- 165 m
2 min ---- 40 m ///////////////////////// 15 min -- 2475 m

Running///////////////////////////////// Resting
1 min --- 165m ////////////////////// 4 min --- 0 m
10 min --- 1650 m
\t\t\t\t
12 min ---- 1690 m /////////////////// 19 min --- 2475 m
X19 ////////X19 ///////////// X 12 ///////X 12\t\t\t\t
228 min ----- 32110 m /////////////// 228 min ---------- 29700 m
\t\t\t
\t\t\t\t\t\t
Combine distance in 228 min is
228 min ----- 61810 m\t\t\t\t\t
? ----- 12000 m \t\t\t\t\t
\t\t\t\t\t
44.26 min .So, 10.00 + 44.26 min ---- 10hr 44 min 26 sec.\t\t

Is this also correct?

[Almighty]

Hi all,

Anyone has the answer for this question?

Mrs Lee was 44 years old.Her son was twice her daugther’s age. \t\t\t\t\t\t\t
Mrs Lee will be twice her son’s age when her daugther is 26 years old. \t\t\t\t\t\t\t
How old will Mrs Lee be when her daughter is 20 years old?

TIA

[Almighty]

Hi VC,


Do u have the link for the answers to the following qts?
1) RGS Prelim 2010 (2 marks)
There are 3 containers X, Y,Z.
One contains blue amrbles, another white and the 3rd one a mixture of blue and white marbles and all are label wrongly.
…
2) Redswastika Prelim 2010 (1 marks)
Kwan chong has a special bicycle as shown below. The bicycle has a large wheel of radius 32……………


TIA

[youngtay]

Hi, Please help


1. Lifen paid $180 for a pair of glasses. The amount she paid includes 7% GST.

a) How much GST did she pay? (Answer given $12.60)
b) What was the sale price of the pair of glasses? (Answer given $180)


2.During a sale, the price of a dining table was reduced from $699 to $350. It was given a further 20% discount on the new price after two weeks. How much was the total discount given? (Answer given $400.20)

Are the answers correct?

TIA