Help with maths :s

[ZainH]

Posted this about 3 times in the "Maths post your doubts!" section , but no reply.. so Im just going to post it as a thread and hopefully there will be an answer by the time I'm done studying. I just need someone to explain to me what the question is asking!
Thanks in advance!

9(iv),(v) b)(iii) (There similiar questions)
http://www.xtremepapers.com/CIE/Cambridge IGCSE/0580 - Mathematics/0580_w10_qp_41.pdf

 

[Razzle-Dazzle]

In part iv they just want you to put the number that you get in iii onto the dotted line (so add it to the other terms). In this case I think it would be 3+6+9+12+1275+150

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w10_ms_41.pdf

Do you have paper 4 tomorrow too?

 

[Razzle-Dazzle]

Wait i'm sorry I just looked at the mark scheme and realized that my answer was wrong. According to them you have to do what I did above but you also have to times the answer from iii by 3. I'm not exactly sure why. I'll have a look and try to get back to you.

 

[Lolagal]

Haha! You had the SAME prob as me but I cleared it out of the way last week, phew! Well, for part (iv) You need to recognise the relation between (iv) and (iii). In that case, you should have noticed that 150 is THREE TIMES 50. So in part (iv) You should JUST multiply the answer you got in part (iii) by 3. Which is 1275. So, 1275*3 = 3,825.


Okay as for part (v) just use the formula given and replace 'n' with 150. So, (1/2)*150(150 + 1) This is equal to 11,325.


In part (vi), the result in part (v) (11,325) is the addition of ALL the numbers from 1 TO 150. BUT, the result you got in part (iv) is the addition of ALL the multiples of 3. So, all you really need to do is subtract the part(v) 's answer from the answer in part (iv). 11,325 - 3825 = 7500. This will help you findthe sum of numbers which AREN'T multiples of 3. AND those dots you see are just representing the numbers that WOULD be there, but obviously the examiners can't write EVERY SINGLE NUMBER, so they just simply put dots instead.

Alright good luck for tomorrow buddy!

 

[ZainH]

Haha! You had the SAME prob as me but I cleared it out of the way last week, phew! Well, for part (iv) You need to recognise the relation between (iv) and (iii). In that case, you should have noticed that 150 is THREE TIMES 50. So in part (iv) You should JUST multiply the answer you got in part (iii) by 3. Which is 1275. So, 1275*3 = 3,825.


Okay as for part (v) just use the formula given and replace 'n' with 150. So, (1/2)*150(150 + 1) This is equal to 11,325.


In part (vi), the result in part (v) (11,325) is the addition of ALL the numbers from 1 TO 150. BUT, the result you got in part (iv) is the addition of ALL the multiples of 3. So, all you really need to do is subtract the part(v) 's answer from the answer in part (iv). 11,325 - 3825 = 7500. This will help you findthe sum of numbers which AREN'T multiples of 3. AND those dots you see are just representing the numbers that WOULD be there, but obviously the examiners can't write EVERY SINGLE NUMBER, so they just simply put dots instead.

Alright good luck for tomorrow buddy!

Thanks alot, theres nothing wrong with your explanation. Your answers are even correct but I still don't get the question :S
"Use your answer to part (iii) to find 3+6+9+12+15+......+150" What kind of question is this? SERIOUSLY?
What are we finding? Where did they get this sequence of numbers.. how could a number like 3825 come before 150.. it doesn't make sense to me :x

 

[Lolagal]

O

Thanks alot, theres nothing wrong with your explanation. Your answers are even correct but I still don't get the question :S
"Use your answer to part (iii) to find 3+6+9+12+15+......+150" What kind of question is this? SERIOUSLY?
What are we finding? Where did they get this sequence of numbers.. how could a number like 3825 come before 150.. it doesn't make sense to me :x

Hahaha I know that's what I told my teacher! I was like, "I just don't get it! What's with the dot dot dot stuff?" SO look, for this question, I advise you to look up the multiples of 3 and add them up. The answer you'd get is 3825! Well, that's if you've got the time...but here's a link to the multiples of 3 http://www.homeschoolmath.net/worksheets/examples/multiples-skip-count-3.htm Alright, add ALL of the multiples from 3 ->150 (It only takes 2 minutes!) and tell me your answer. The dot dot dot thing = sum of multiples of 3. I'm not sure if I made sense :/ but once again this is IGCSE and nothing is meant to make sense!

 

[ZainH]

O


Hahaha I know that's what I told my teacher! I was like, "I just don't get it! What's with the dot dot dot stuff?" SO look, for this question, I advise you to look up the multiples of 3 and add them up. The answer you'd get is 3825! Well, that's if you've got the time...but here's a link to the multiples of 3 http://www.homeschoolmath.net/worksheets/examples/multiples-skip-count-3.htm Alright, add ALL of the multiples from 3 ->150 (It only takes 2 minutes!) and tell me your answer. The dot dot dot thing = sum of multiples of 3. I'm not sure if I made sense :/ but once again this is IGCSE and nothing is meant to make sense!

Hmm Ill try this, thanks again! Good luck in your exam tomorrow, I'll go and study a bit and then go to sleep.
Pray for me x)

 

[Hamzeh S]

hey the next page last questions i wrote the formula but i dont know how to simpify it ? any help

 

[ZainH]

O


Hahaha I know that's what I told my teacher! I was like, "I just don't get it! What's with the dot dot dot stuff?" SO look, for this question, I advise you to look up the multiples of 3 and add them up. The answer you'd get is 3825! Well, that's if you've got the time...but here's a link to the multiples of 3 http://www.homeschoolmath.net/worksheets/examples/multiples-skip-count-3.htm Alright, add ALL of the multiples from 3 ->150 (It only takes 2 minutes!) and tell me your answer. The dot dot dot thing = sum of multiples of 3. I'm not sure if I made sense :/ but once again this is IGCSE and nothing is meant to make sense!

I UNDERSTOOOD :O
I was just reading over the question and your post yesterday and I got it!
THANK YOU THANK YOU THANK YOU x)

 

[FATIMA1996]

helloo can someone help me... can anybody tell me how to find the 64th percentile

 

[ZainH]

helloo can someone help me... can anybody tell me how to find the 64th percentile

64th percentile means 64%. Just find 64% of whatever number your given x)

 

[FATIMA1996]

thanks sooo much btw where are you doing your exam i mean which country

 

[FATIMA1996]

hello there i also need help in this like which line d0 we draw
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s11_qp_41.pdf
QP 7 E

 

[Lolagal]

I UNDERSTOOOD :O
I was just reading over the question and your post yesterday and I got it!
THANK YOU THANK YOU THANK YOU x)

Oh, it's okay, I answered this because I was sure of my answer, and I was also determined to make you understand. It's GREAT that you did! Hope you've done well! :]

 

[ZainH]

Oh, it's okay, I answered this because I was sure of my answer, and I was also determined to make you understand. It's GREAT that you did! Hope you've done well! :]

Well even though I understood there were no questions like that :S
Still, paper went amazing. Like it was craazyyy easy x) How was yours?

 

[Lolagal]

You did paper 42 right? It went really good! Most of the things like transformation and cumulative frequency were in paper 2 so that's why they didn't come and the sequences part was like 2 questions.

 

[ZainH]

You did paper 42 right? It went really good! Most of the things like transformation and cumulative frequency were in paper 2 so that's why they didn't come and the sequences part was like 2 questions.

Yup paper 42! Thank god there were no transformations of C.Frequencies in paper 4.. they would've been 20x harder then those in paper 2.
The sequence questions were a piece of cake x)

 

[Lolagal]

Yup paper 42! Thank god there were no transformations of C.Frequencies in paper 4.. they would've been 20x harder then those in paper 2.
The sequence questions were a piece of cake x)

My fave part was finding the angles...halfway through the exam I was like this is fuuuun!

I still did some silly mistakes though haha I'm sure I lost about hmmm....10-15 marks. Just an approximation haha

 

[ZainH]

My fave part was finding the angles...halfway through the exam I was like this is fuuuun!

I still did some silly mistakes though haha I'm sure I lost about hmmm....10-15 marks. Just an approximation haha

Those angles were annoying -_-
Especially the reasoning... but yeah I think I lost around 10 marks as well :S

 

[Lolagal]

Those angles were annoying -_-
Especially the reasoning... but yeah I think I lost around 10 marks as well :S

Well I'm finding out there were some tricks! What's this whole thing about the bounds? :[ I'm getting so freaked out hahhaa but I'm pretty sure above 90 something is an A* and everything, hopefully everyone did well!