can someone post the link to the gcse olevels timetable OCT/NOV 2012

[Waleed007]

yeah you always make the left hand side value as the numerator, thats how i remeberd.

Learn formulas as well, which is very important!

 

[aalmuhannadi]

Alright i got this thanks so it says find y when x is 10, so we will do :

y=kx^2
y=0.125 (10)^2
y=0.125x100
y= 12.5

am i right?

You got it correct

 

[zainabkhann]

Alright thanks guys i need help in significant numbers, i never understand them, even when people send me links, i want someone to explain it to me with examples.

 

[Waleed007]

Here check this:

 

[zainabkhann]

Would this be considered a formula book? See on page three where it has the percentage points it says SP-CP, whats that?

 

[zainabkhann]

its the same, check page three on it

 

[aalmuhannadi]

Alright thanks guys i need help in significant numbers, i never understand them, even when people send me links, i want someone to explain it to me with examples.

It's basically has to do with rounding. For example, if you have a number like 315.94826 and you had to round it to 2 significant figures, all you do is select the 2nd number from the left (which is 1) and check the number after it. If the number after it is between 5 and 9, you round up the previous number, making the 1 into a 2. If the number after it is between 1 and 4, then you round down, keeping the 1 as itself. After rounding up or down, all other numbers after it become zero. e.g. in 315.94826, If you round to 2 s.f., you get 320.00000. Because the number after the 1 was a 5, we had to round the 1 up to a 2, then make all the numbers after it a 0.

If you get a number which is a decimal e.g. 3.142, and you had to round it to, let's say, 2 s.f. for example. You do the same thing. Select the 2nd number from the left, which is a 1. Check the number after it, which is a 4. It's between 1 and 4, so we have to round down the 1. The 1 stays as a 1 and doesn't change since we round down and not up. So we end up with 3.100, or just 3.1. Hope that helped?

 

[Waleed007]

Would this be considered a formula book? See on page three where it has the percentage points it says SP-CP, whats that?

It means Selling price - Cost price = Profit

 

[zainabkhann]

It means Selling price - Cost price = Profit

okey thanks , can you tell me how to solve questions which say:

x in terms of y or something, when u have to rearrange the whole formula to make x in the right hand side, its very frustrating for me to understand.

 

[aalmuhannadi]

Would this be considered a formula book? See on page three where it has the percentage points it says SP-CP, whats that?

CP is cost price and SP is selling price.

 

[aalmuhannadi]

okey thanks , can you tell me how to solve questions which say:

x in terms of y or something, when u have to rearrange the whole formula to make x in the right hand side, its very frustrating for me to understand.

Can you give an example?

 

[zainabkhann]

It's basically has to do with rounding. For example, if you have a number like 315.94826 and you had to round it to 2 significant figures, all you do is select the 2nd number from the left (which is 1) and check the number after it. If the number after it is between 5 and 9, you round up the previous number, making the 1 into a 2. If the number after it is between 1 and 4, then you round down, keeping the 1 as itself. After rounding up or down, all other numbers after it become zero. e.g. in 315.94826, If you round to 2 s.f., you get 320.00000. Because the number after the 1 was a 5, we had to round the 1 up to a 2, then make all the numbers after it a 0.

If you get a number which is a decimal e.g. 3.142, and you had to round it to, let's say, 2 s.f. for example. You do the same thing. Select the 2nd number from the left, which is a 1. Check the number after it, which is a 4. It's between 1 and 4, so we have to round down the 1. The 1 stays as a 1 and doesn't change since we round down and not up. So we end up with 3.100, or just 3.1. Hope that helped?

omg that didnt help im sorry, i just dont get this at all, cant follow through. can you start from a basic example first, i never really got rounding from the beginning.

 

[zainabkhann]

Sure

Can you give an example?

Like: from paper 1, year 1997, question 21

Given that: s= 3/t-2

Express t in terms of s

 

[aalmuhannadi]

omg that didnt help im sorry, i just dont get this at all, cant follow through. can you start from a basic example first, i never really got rounding from the beginning.

You don't know rounding? Well rounding is basically changing a number to make it less confusing I guess. Like if you round 6 to the nearest 10, you'd have to round up rather than down, because 6 is closer to 10 than it is to 0. Rounding 143 to the nearest 100 would mean it would be 100 not 200, because it's closer to 100 than it is to 200. Rounding 6392 to the nearest thousand would round it to 6000 because it's closer to 6000 than it is to 7000. Rounding it to the nearest hundred would be 6400 because it's closer to 6400 than it is to 6300. Rounding it to the nearest ten would make it 6390 because it's closer to 6390 than it is to 6400. Those are the basics of rounding, if you didn't get that then I don't know how else to explain it I'm sorry :/

 

[Waleed007]

okey thanks , can you tell me how to solve questions which say:

x in terms of y or something, when u have to rearrange the whole formula to make x in the right hand side, its very frustrating for me to understand.

Let's take an example:
Rearrange the formula so that x is expressed in terms of y and z.
y = x + 7z
This means you need a formula for x
Begin the process by swapping the two sides of your formula.
x + 7z = y
Now on the left hand side 7z is being added to x. So take 7z off both sides.
x = y – 7z.

 

[aalmuhannadi]

Sure


Like: from paper 1, year 1997, question 21

Given that: s= 3/t-2

Express t in terms of s

I can't find that paper on here, can you please upload it?

 

[zainabkhann]

You don't know rounding? Well rounding is basically changing a number to make it less confusing I guess. Like if you round 6 to the nearest 10, you'd have to round up rather than down, because 6 is closer to 10 than it is to 0. Rounding 143 to the nearest 100 would mean it would be 100 not 200, because it's closer to 100 than it is to 200. Rounding 6392 to the nearest thousand would round it to 6000 because it's closer to 6000 than it is to 7000. Rounding it to the nearest hundred would be 6400 because it's closer to 6400 than it is to 6300. Rounding it to the nearest ten would make it 6390 because it's closer to 6390 than it is to 6400. Those are the basics of rounding, if you didn't get that then I don't know how else to explain it I'm sorry :/

i totally got this, but dont get signiicant numbers, like it would give me a big number and would ask me to round 2 significant numbers, can you just give me a simple number and round it to 2 sig numbers and then give me a complicated number so i understand better?

 

[zainabkhann]

I can't find that paper on here, can you please upload it?

i actually got it from my past paper book, thats all i can give im afraid. You can write it down so its easier.

 

[Waleed007]

i actually got it from my past paper book, thats all i can give im afraid. You can write it down so its easier.

Well, I got it!
As it's written S=3/t-2
First take t-2 on the left hand side
and take 'S' to the denominator that will be t-2=3/s
so, to make the t the subject, -2 will be converted in +2 and take it to the right hand side
t=3/s+2

 

[aalmuhannadi]

i actually got it from my past paper book, thats all i can give im afraid. You can write it down so its easier.

s = 3 / t-2
We need to make t the subject of the formula.
First of all, multiply both sides by 't-2' in order to get rid of the fraction
Then we have s(t-2) = 3
Simplify it to ts - 2s = 3
Add 2s to both sides in order to have ts on its own: ts = 3 + 2s
Then divide both sides by s in order to get t on its own: t = 3 + 2s / s