practice school certificate help. (1 Viewer)

[Riot09]

long story short the school certificate is around 30 something days away and i suck at math.im good at history and english and know what and how to sudy for those and the geography,commerce,ist and the science tests because its simply reading and writing.whereas math contains variables and procedures that have to be rote learn't.so i need help with a few questions that i can't figure out by myself or just looking at the answers..all answers will be appreciated and please put in working out and a expanation... thank you

my email is relax187@yahoo.com.au so just send anything else you have that can help there if you can't put it here.

these are the questions.

1.the volume of a cylinder is given as v=pi r^2 h.what is the value of r if v=905 and h=18?

2.frank has to include a stamped sel-adressed envelope in a letter he is about to post.He has no 50c stamps but he has one 30c, one 20c and 10 5c stamps.How many different value combinations (of 50c) of stamps can be made? (is there a quick way to do this question because its only worth 1 mark)

3.which pair of equations could the following lines represent (4,-4) and (-4,-4)
the answer is y=-x+4 and y=x-4. but how?

4.a ratepayer pays 0.3158cents in the dollar on land valued at $172 000.How much is this?

5.Sally is making stars for christmas decorations.To make regular 5 pointed stars she divides circles equally to get 5 marks for points.If she joins the 5 points to the centre what will each angle,at the centre,measure?

5.montly repayments.payments have been calculatered at 16% per annum reducible.All amounts have been rounded up to the nearest dollar.

(a).how much interest will be paid on a loan of $7500 paid back over 10 years?

(b).how much extra will it cost if $9000 is borrowed over 15 years instead of 5?

(c).Jim borrowed $5000 for 5 years.What was the interest as a flat rate?

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?

9.Bruce makes and sells furniture.If it costs him $550 to make a lounge how much must he sell it for if he needs to make a profit of 45% on the cost?

10.Amy's cousin ted who lives 35km away has just rung to say he is leaving home on his way to visit amy.he will travel 12km at 60km/h and the remainder at 50km/h.how long can she expect him to take to get to her place?
(is there a short way of doing this question)?

11.if 2 dice are thrown what is the probability of throwing a total higher than 10?(is there a short way of doing this also)?

thank you for reading this and for the help.

 

[muzeikchun852]

1.the volume of a cylinder is given as v=pi r^2 h.what is the value of r if v=905 and h=18?.

905 = pi r^2 x 18
905/(pi x 18) = r^2
u do the answer urself.

2.frank has to include a stamped sel-adressed envelope in a letter he is about to post.He has no 50c stamps but he has one 30c, one 20c and 10 5c stamps.How many different value combinations (of 50c) of stamps can be made? (is there a quick way to do this question because its only worth 1 mark)

proporly not..
u just have to list it.

3.which pair of equations could the following lines represent (4,-4) and (-4,-4)
the answer is y=-x+4 and y=x-4. but how?

y=(x value)x + (y value)

4.a ratepayer pays 0.3158cents in the dollar on land valued at $172 000.How much is this?

0.003158 x 172000 = answer.

5.Sally is making stars for christmas decorations.To make regular 5 pointed stars she divides circles equally to get 5 marks for points.If she joins the 5 points to the centre what will each angle,at the centre,measure?

i dont get that either..

5.montly repayments.payments have been calculatered at 16% per annum reducible.All amounts have been rounded up to the nearest dollar.

(a).how much interest will be paid on a loan of $7500 paid back over 10 years?

(b).how much extra will it cost if $9000 is borrowed over 15 years instead of 5?

(c).Jim borrowed $5000 for 5 years.What was the interest as a flat rate?

(a) 7500 x (1 + 0.16)^10 - 7500 = answer
(b) 9000 x (1 + 0.16)^15 - 7500 = answer
(c) [5000 x (1 + 0.16)^5 - 5000] / 5000 x 100% = answer

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)

100000 cm / 28pi = answer.

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?

(a) 6000/52 = answer.
(b) 6000/52/12 = answer.

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

(0.6 x 4 + 0.7) / 5 = answer..
easy.

9.Bruce makes and sells furniture.If it costs him $550 to make a lounge how much must he sell it for if he needs to make a profit of 45% on the cost?

500 x 1.45 = answer.

10.Amy's cousin ted who lives 35km away has just rung to say he is leaving home on his way to visit amy.he will travel 12km at 60km/h and the remainder at 50km/h.how long can she expect him to take to get to her place?
(is there a short way of doing this question)?

12 / 60 + 23/50 = answer in hours.

11.if 2 dice are thrown what is the probability of throwing a total higher than 10?(is there a short way of doing this also)?

x 1 2 3 4 5 6
1 x x x x x x
2 x x x x x x
3 x x x x x x
4 x x x x x x
5 x x x x x
6 x x x x

answer = 3/36 = 1/12

 

[Omnipotence]

Sally is making stars for christmas decorations. To make regular 5 pointed stars she divides circles equally to get 5 marks for points. If she joins the 5 points to the centre what will each angle, at the centre, measure?

Q5. Draw a five point star inside a circle, let the edges of the star lay on the circumference. You get ten sides for for the star. Then you place it in the general formula of a regular polygon;

One angle = (n-2) x 180° / n, where n = the number of sides. Substitute n = 10 into the equation.

Therefore, (10 - 2) x 180° / 10 = 144° for each angle.

 

[ninetypercent]

2.frank has to include a stamped sel-adressed envelope in a letter he is about to post.He has no 50c stamps but he has one 30c, one 20c and 10 5c stamps.How many different value combinations (of 50c) of stamps can be made? (is there a quick way to do this question because its only worth 1 mark)

Just list them.

30 + 20
30 + (5cx4)
20 + (5cx6)
(10x5c)

4 ways.

 

[angels2]

(a) 7500 x (1 + 0.16)^10 - 7500 = answer
(b) 9000 x (1 + 0.16)^15 - 7500 = answer
(c) [5000 x (1 + 0.16)^5 - 5000] / 5000 x 100% = answer



i dont get this. isn't that the formula for compound interest? ...im lost.
could you probably also type the whole question up. if you have then im sorry about that.

 

[ninetypercent]

5.montly repayments.payments have been calculatered at 16% per annum reducible.All amounts have been rounded up to the nearest dollar.

(a).how much interest will be paid on a loan of $7500 paid back over 10 years?

(b).how much extra will it cost if $9000 is borrowed over 15 years instead of 5?

(c).Jim borrowed $5000 for 5 years.What was the interest as a flat rate?

This is the question. yes its compound interest formula, except the condition is that it is reducible, meaning that u pay as u go.