Maths...school certificate test 2008 non-calculator solutions and working out please. (1 Viewer)

[Riot09]

7^2=100-6x10+9
17^2=400-6x20+9
27^2=900-6x30+9
37^2=?

thegold in pharoah tutankhamen's coffin has a mass of 110kg.

if 1 gram of gold is worth $30,what is the value of the gold in the coffin?

chris is buying a new car

this car can be
.a hatchback,sedan or wagon
.red,blue,yellow,white or back
.manual or automatic

using this information,how different choices of car does chris have?

working out and explanation...please would be appreciated thank you

6.A wheel has a diameter of 28cm.How many revolutions will it make to cover 1 km.(is there a short way of doing this question)

7.Jamie does odd jobs at $12 per hour.He aims to keep below the tax threshold of $6000 per year.

(a).what is the maximum amount per week that he can earn and be below this?

(b).how many hours would this be?

8.Ezra has a mean of 60% for 4 exams.he received 70% for the next exam.what is the new mean?


<ABBR title="2009-10-07 02:26:30">22 hours ago</ABBR>

 

[mirakon]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

Q1. Initially, note that

7^2=100-6x10+9 (where 100 is (1^2)x100) and 6x10 is 1x6x10
17^2=400-6x20+9 (where 400 is (2^2)x100) and 6x20 is 2x6x10
27^2=900-6x30+9 (where 900 is (3^2)x100) and 6x30 is 3x6x10

See the pattern now?

Now as this is a SC test and knowledge is fairly basic we can assume the following pattern is true such that:

37^2=1600-6x40+9 (where 1600 is (4^2)x100) and 6x40 is 4x6x10

Ans: 1369 (just check this is accurate as I did it in my head)

Q2. Convert kilograms into grams at first,

110kg= 1000x110g= 110000g

1g= $30 (given)

Therefore,

110000g= $3300000

Ans: $3300000

Q3. Visualise the following

Hatchback+Sedan+Wagon= 3 choices
Red+Yellow+Blue+White+Black= 5choices
Manual+Automatic= 2 choices

For each of the 3 car choices there are 5 colour choices and a manual or automatic choice.

So, this is the same as saying 3x5x2

3x5x2= 30 choices

Ans: 30

Just check these solutions are accurate as I did them in my head. Hope I have been of help.

 

[mirakon]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

I'll post the rest of the solutions soon, accidentally missed them the first time.

 

[mirakon]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

Q7. There are approx 52 weeks in a year (if you can't remeber this do 365/7 representing days in a year divided by days in a week)

Do the following calculation 6000/52 which is approximately $115.38 (note this is slightly below $6000 as requried but the closest amount to it.

But it has to be divisible by $12 so closest multiple of 12 to 115 is 108

Ans: $108

Q8. Mean for first 4 exams was 60%. This is equivalent to saying that Ezra got 60x4= 240 total marks in her first four exams.

She got 70% in her fifth exam so hence

240+70= 310 marks in total for all five exams.

Divide sum by number of elements to get mean, so:

310/5=62%

Ans: 62%

Q6. What do you mean by shorter way? I need to know your solution so I can get an idea if that is the only way to do it. Sometimes there is no easier way in questions.

Hope I've helped.

 

[Riot09]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

alright thanx

 

[supre]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

can someone please explain question 6 and 8 thoroughly.
thanks in advance

 

[mirakon]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

Explain as in explain answer or question?

 

[supre]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

explain the answer once more please (more working out)

 

[Amogh]

Re: Maths...school certificate test 2008 non-calculator solutions and working out ple

can someone please explain question 6 and 8 thoroughly.
thanks in advance

6. Firstly, 1km = 1,000m= 100,000 cm.
The circumference of the wheel = pi*d = pi*28
We now divide the total distance by the circumference, as we want to know how many revolutions (turns, which is just the circumference) will it need to travel the distance.
So, 100000/pi*28 = 1137 approx

8. Mean of 60% for four exams = .6 for four exams
The total marks for the 4 exams is = .6 * 4 = 2.4 [mean = total marks /number of exams...and so total marks= number of exams * mean]
The 5th mark is .7
and so the new mean is (2.4 + .7)/5 = .62 or 62%

6.A wheel has a diameter of 28cm.How many revolutions will it make to cover 1 km.(is there a short way of doing this question)

7.Jamie does odd jobs at $12 per hour.He aims to keep below the tax threshold of $6000 per year.

(a).what is the maximum amount per week that he can earn and be below this?

(b).how many hours would this be?

8.Ezra has a mean of 60% for 4 exams.he received 70% for the next exam.what is the new mean?

I am positive you have asked these questions already. Could you please not reiterate questions.

And bombard the questions in ONE thread

physically ask your peers more, and actually imo you need a tutor.