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#1 Help Me ! » Urgent maths questions » 2010-03-15 00:02:22

Karn
Replies: 17

A frog down the bottom of a well is able to climb up 5 metres in one hour. However, the frog then has to rest for an hour in which time it slides back 3 metres in the next hour before resting and sliding back 3 metres in the hour after that and so on.

1) Intially the frog is at the bottom of a well is 21 mtres deep. How long does it take to get out of the well: I got 17 hours

2) if the well was 26 metres deep

I got 23 hours

3) can you find the rule which connects the depth of the well to a the time it takes to get out : I dont get this one/

Then there is a Table

Depth        Time
1                1
2                1
3                1
4                1
5                1
6                3
7                3
8                5
9
10
11
12
13
14
15
16
17
18
19
20


I get the 5 1s part but not the rest

Plase help thank you for any hel smile

#2 Help Me ! » Conditional probability » 2010-03-01 23:22:54

Karn
Replies: 2

Urgent. Studying for a test however in this revision task I having trouble with the following questions.
Q.A normal six sided die is rolled twice and the scores obtained are added together.
   Event A is that of the first roll giving a 5
   Event B is that of the total being 10

Determine (a) P(B:A)  (b) P(A:B)

Event C is that of the first roll giving a 2
Event D is that of the total being 6

Determine (c) P(D:C)   (d) P(C:D)

Event E is that the first roll giving an odd number
Event F is that of giving the total being 5

determine (e) P(F:E)   (f) P(E:F)

Help is greatly appreciated lol

Thank you:)

#3 Help Me ! » Number: Scientific notation, significant figures and so on » 2010-02-01 23:18:47

Karn
Replies: 1

Hi Everyone!

Q.1) To the nearest square centimetre a solid cube has a total surface area of 1090 cm^2
           
a) Determine the length of each of the cubes edges giving your answer in millmetres, to the nearest millimetre         
b) Determine the volume of the cube giving your answer to the nearest  10cm^3

Q.2) Australia has a land area of approximately 7.68 X 10^6 square kilometres and a population of approximately 20 million.

a)    How many square kilometres is that for each person?
b)    How many people is that for each square kilometre?

And finally

Q.3) Evaluate each of the following giving your answers in scientific notation and correct to 3 significant figures.

a) (7.48 X 10^3)  X (6.34 X 10^6)

For this one I got…

4.74 X 10^9 (which is of course is incorrect however how do solve this without a calculator)

I thought when you multiply numbers with powers you add the powers together but  with this one instead of 10^9 by adding 3 and 6 the correct answer is 4.74 X 10^10
Please explain.

Thank you very much for any help.

#4 Help Me ! » Quadratic Functions » 2010-01-14 19:19:28

Karn
Replies: 0

Hello

A dog owner wishes to enclose a rectangular area in his backyard for the dog. The owner wishes to use existing fencing along two adjacent sides of the rectangle and has 14 metres of new fencing available for the other two sides. Suppose that we let the dimensions of the rectangle be x metres and y metres and the area be Am^2 as shown below.


c) With a on the vertical axis and x on the horizontal axis make a sketch of A= x(14-x)

For this question I have found the turning point which is x=7, the nature and location of the turning point -maximum turning point which occurs at the coordinates of (7,49), the y-axis intercepts which is A=0 with coordinates of(0,0) and the x-intercepts to sketch this equation  and checked it on the graphic calculator...

My question is when writing down the x-intercepts do I write x=0 or x=14 or x=0 and x=14


Thank you

#5 Help Me ! » Factorisation » 2009-12-30 22:16:05

Karn
Replies: 1

Hi

I am stuck on this question

1) When an object is projected upwards from ground level, with initial speed 40 m/s, the height it is above ground t seconds later is h metres where h is given by:           h ≈ 40t - 5t^2
State the value of h when the object hits the ground again and find the value of t then.

Thank you

#6 Help Me ! » another Indices question » 2009-12-21 18:13:50

Karn
Replies: 3

Hello

How do find the value of n in the following

(1+n/8)^2 = 1 17/64

I fist converted the fraction into a improper fraction and used the 'power of a quotient law' but then I was stuck.

Thank you for any help

#7 Re: Help Me ! » Indicies » 2009-12-20 19:51:19

Karn

Thank you

#8 Help Me ! » Indicies » 2009-12-20 19:20:43

Karn
Replies: 2

How you find the the value of n in the following.

2^8 ÷ 8 = 2^n

Thank you

#9 Re: Help Me ! » Number and Algebra » 2009-11-23 14:28:03

Karn

Thank you

also

How would yous solve b) without a calculator?

#10 Help Me ! » Number and Algebra » 2009-11-22 18:15:57

Karn
Replies: 7

Hello

Solve graphically

(a)         (x+3)(x+2)= 10

(b)        -2x^3 + 3x^2 - 1=4

c)          y= 2x+ 3 and x= 2y + 1


What does it mean to 'solve graphically'

Thank you for any help provided.

#11 Help Me ! » Trigonometry » 2009-11-18 16:17:35

Karn
Replies: 8

Hello

I'm having trouble with this question.

In the diagram below, triangle ACD is isosceles with an area of 32m^2 and AD is 11.31m in length whilst angle B has been set 56º. Find the length of BD.

Thank you for any help

cheers

#12 Re: Help Me ! » The Sine Rule » 2009-11-15 22:59:47

Karn

oops here it is

#13 Help Me ! » The Sine Rule » 2009-11-15 22:54:17

Karn
Replies: 3

I don't know how to solve the following problem (on the attatchement).

Thank you for any help

#14 Introductions » Hello » 2009-11-15 22:52:29

Karn
Replies: 3

Hi everyone

I am looking foward to asking questions. I think this maths forum is the best ever on the internet.

cheers

Karn

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