***2015 JC Maths Paper 1 - all levels - June 5th 2015***

spurious

For discussion of the exams AFTER they have been held.

Please indicate which level paper you are talking about.

ylroy

HL- Most of them were okay but there were 3 particular sections in the questions that werr very difficult: Conversion of formula, finding the gross wage and Pythagoras. I hopefully get a low B or a High C. I wish paper 2 would be easier and boost my grade a little bit.

frans123

Higher Level : Easy , Except for one or two parts like the very last part of question and finding gross profit

DaleyBlind

Did badly on Q3 and Q14 d. Was it just me that thought there was a mistake in Q10 or I am just wrong? In the question about sets, it said:
18 had measles
40 had chickenpox.

Shouldn't it have said:
18 had only measles
40 had only chickenpox?

The reason I think this is because if you add them all up in the first on it's 85. If you add them all up with only written it's 100. And there is a difference between saying 'only' and not saying it.

frans123

mine added fine

gazump123

Higher level. Found the paper really easy bar the last part of the last question.

ylroy

DaleyBlind wrote: »

Did badly on Q3 and Q14 d. Was it just me that thought there was a mistake in Q10 or I am just wrong? In the question about sets, it said:
18 had measles
40 had chickenpox.

Shouldn't it have said:
18 had only measles
40 had only chickenpox?

The reason I think this is because if you add them all up in the first on it's 85. If you add them all up with only written it's 100. And there is a difference between saying 'only' and not saying it.

I think if they hadnt said it, you should subtract the one they have in common ie. their intersections

DaleyBlind

ylroy wrote: »

I think if they hadnt said it, you should subtract the one they have in common ie. their intersections

Yeah it didn't write only so after subtracting the intersections I ended up with only 85 in total so I'm not sure where I went wrong.

UnknownEntity

Thought that exam was so easy.
I'm pretty sure I got all the questions correct.

GJAerLingus

Ordinary Level.
It went pretty well. All the questions were easy except for one of the last ones which had something along the lines of:
"Multiply K by 3 and take 5 away" Didn`t quite get it.

gazump123

GJAerLingus wrote: »

Ordinary Level.
It went pretty well. All the questions were easy except for one of the last ones which had something along the lines of:
"Multiply K by 3 and take 5 away" Didn`t quite get it.

3K - 5?

Mldj

HL. Definitely got 100%. Thought the paper was very nice.
I felt that q6 was not clear as to whether the data was continuous or discrete, and it was therefore unclear whether one should use a dashed line or a solid line.

GJAerLingus

gazump123 wrote: »

3K - 5?

Thats what I said, talked to someone afterwards and they said they got a completely different answer. Hope I get some marks for it anyway.

conorfinn1

Thought the paper overall was grand.
I probably got a C in it though, I may be harsh on myself, didn't answer one part. Gave everything else every attempt I could.

gazump123

Mldj wrote: »

HL. Definitely got 100%. Thought the paper was very nice.
I felt that q6 was not clear as to whether the data was continuous or discrete, and it was therefore unclear whether one should use a dashed line or a solid line.

Which question was that? The mobile data one?

patrickLouth1

HL- I am very confident i got an A on that paper
Does anyone know the solution for
Explain why t100=t98 + t97

gazump123

patrickLouth1 wrote: »

HL- I am very confident i got an A on that paper
Does anyone know the solution for
Explain why t100=t98 + t97

I said because in this instence Tn-1 + Tn-2 is always equal to Tn. e.g.
t1 + t2 = t3
1 + 2 = 3
3 = 3

Have no idea if its right though.

Kbvdpo

gazump123 wrote: »

I said because in this instence Tn-1 + Tn-2 is always equal to Tn. e.g.
t1 + t2 = t3
1 + 2 = 3
3 = 3

Have no idea if its right though.

I said that too! I hope it's right!

patrickLouth1

gazump123 wrote: »

I said because in this instence Tn-1 + Tn-2 is always equal to Tn. e.g.
t1 + t2 = t3
1 + 2 = 3
3 = 3

Have no idea if its right though.

Sounds right
What did you get for using an algebraic formula to express k as F
For the kelvin question

patrickLouth1

Kbvdpo wrote: »

I said that too! I hope it's right!

Wait what did you get t1 and t2 to equal to?

DaleyBlind

patrickLouth1 wrote: »

Sounds right
What did you get for using an algebraic formula to express k as F
For the kelvin question

I said 5(459.67 + F) over 9.

UnknownEntity

It's because each Tn equaled the two previous added together.

E.g:t(3)=t(2)+t(1)
t(5)=t(4)+t(3)

I know that looks wrong but I'm refering to how many possible combinations there were, not the actual number of the step.

Saying that t(1) and t(2) is equal is wrong because that's not right. You would have to say that the possible combinations were equal, not the number of the step because that logic doesn't work after t(3).

patrickLouth1

haiyna wrote: »

It's because each Tn equaled the two previous added together.

E.g:t(3)=t(2)+t(1)
t(5)=t(4)+t(3)

I know that looks wrong but I'm refering to how many possible combinations there were, not the actual number of the step.

Saying that t(1) and t(2) is equal is wrong because that's not right. You would have to say that the possible combinations were equal, not the number of the step because that logic doesn't work after t(3).

I actually said that haha so happy i didnt know what i was saying but i guess i was right

patrickLouth1

What did y'all ger for part (iii) on the function one i think it was q4 you had to solve for k,well i think it was K

Mantis1234

I found the ordinary paper very easy, almost too easy. Also, did anyone find it strange how there was only 12 questions?

UnknownEntity

I got 3k+5=k
2k=-5
K=-5/2

ylroy

haiyna wrote: »

They're going to have do something about that paper's marking scheme because by the looks of it way too many people got A's.

Can't wait for Paper 2, that's my better paper and I think everything was right in paper 1. ðŸ˜႒

No offense, but I think you should be delighted that people are getting good marks for once and for all.

pitapattern

Hey can anyone tell me which was the question about airplanes, I can't remember! Just saw it in the Irish Times and I don't remember what it relates to, help!

spurious

pitapattern wrote: »

Hey can anyone tell me which was the question about airplanes, I can't remember! Just saw it in the Irish Times and I don't remember what it relates to, help!

It was on the LC Higher paper.

pitapattern

spurious wrote: »

It was on the LC Higher paper.

Thank God the Irish Times got it wrong! I was so worried! Phew!

Thanks.

Mldj

gazump123 wrote: »

Which question was that? The mobile data one?

Ye.

james_jog99

Found the paper easy as hell. Was finished after 1 hr and had the next 90 mins to look back. The only question I had slight trouble bit was the second part of tax one where you were working backwards and ended up just doing trial and error until I found it. I'm pretty sure I got at least 90% and I'm hoping for 95%+ (I know they don't tell you the percent) as I am planning to do mainly maths subjects for LC as I like it.

PS I had studied the Fibonacci sequence (last question) in maths enrichment classes so that was extremely easy for me.

Well I hope I can do well in p2 to back up that solid p1 performance!

james_jog99

patrickLouth1 wrote: »

HL- I am very confident i got an A on that paper
Does anyone know the solution for
Explain why t100=t98 + t97

Consider it this way. If at first I go up one step I am at step 99 and from there every way I can do it will be in t99 cuz it's like I am starting from the 99th step, but if I go up 2 steps the same principal will apply but for t98. Therefore t98 + t99 = t100 because you can only go up either 1 or 2 steps to start with.

UnknownEntity

james_jog99 wrote:

Found the paper easy as hell. Was finished after 1 hr and had the next 90 mins to look back. The only question I had slight trouble bit was the second part of tax one where you were working backwards and ended up just doing trial and error until I found it. I'm pretty sure I got at least 90% and I'm hoping for 95%+ (I know they don't tell you the percent) as I am planning to do mainly maths subjects for LC as I like it.

This is how you do that gross wage question.

Gross wage: x
Standard tax: 6760
Higher tax: 0.4(x-33,800)
Tax credits: 3300
Net wage:34,780

x-6760-(0.4x-13,520)+3300=34,780
0.6x=34,780+6760-13,520-3300
0.6x=24,720
x=41,200

That is the correct answer because: (41,200-33,800)x0.4=2960
2960+6760=9720
41,200-9720=31,480
31,480+3300=34,780 which is her net profit that was given in the question.

james_jog99

haiyna wrote: »

This is how you do that gross wage question.

Gross wage: x
Standard tax: 6760
Higher tax: 0.4(x-33,800)
Tax credits: 3300
Net wage:34,780

x-6760-(0.4x-13,520)+3300=34,780
0.6x=34,780+6760-13,520-3300
0.6x=24,720
x=41,200

That is the correct answer because: (41,200-33,800)x0.4=2960
2960+6760=9720
41,200-9720=31,480
31,480+3300=34,780 which is her net profit that was given in the question.

Thanks for posting that. I ended up just using the process from part one like ten times but I did get 41,200 as my answer so hopefully I'll get the marks.

UnknownEntity

james_jog99 wrote:

Thanks for posting that. I ended up just using the process from part one like ten times but I did get 41,200 as my answer so hopefully I'll get the marks.

Well you must have done something right because that is a very hard number to get to by chance!

gj kg hjjjj

how to
do question 4 pls?

UnknownEntity

A: 3(7)+5
21+5
26

B: 3K+5

C: 3K+5=K
2K=-5
K=-5/2

Hope that helps!

james_jog99

gj kg hjjjj wrote: »

how do question 4 pls?

i) f(7) = 3(7) + 5
F(7) = 26

ii) f(k) = 3(k) + 5
F(k) = 3k + 5

iii)
F(-3) = -4
F(-2) = -1
Therefore it's between -3 and -2
F(-2.5) = 3(-2.5) +5
F(-2.5) = -7,5 + 5
F(-2.5) = -2.5

gj kg hjjjj

Any one know the question with the simultaneous equations?

gj kg hjjjj

james_jog99 wrote: »

i) f(7) = 3(7) + 5
F(7) = 26

ii) f(k) = 3(k) + 5
F(k) = 3k + 5

iii)
F(-3) = -4
F(-2) = -1
Therefore it's between -3 and -2
F(-2.5) = 3(-2.5) +5
F(-2.5) = -7,5 + 5
F(-2.5) = -2.5

Did you do the paper today?

gj kg hjjjj

gj kg hjjjj wrote: »

Any one know the question with the simultaneous equations?

No I'm talking about the one with b and c question 12

Kbvdpo

How was q13 done?

Also was is right to answer t100=t99 + t98 with:

T3 = t2 + t1
3=2+1
3=3

james_jog99

gj kg hjjjj wrote: »

Any one know the question with the simultaneous equations?

i)
You know h(1) = 5 so you know 2(1)^2 + b(1) + c = 5 so that's equation 1 which when worked out is b + c = 3
Repeat for h(2) = 13 and you will end up with equation 2 which is 2b + c = 5

ii)
Times equation 1 by -1 so the c's cancel and you get b= 2. Now you can fill b=2 into and equation above eg (2) + c = 3 and you get c= 1 which are the answers for the question

james_jog99

Kbvdpo wrote: »

How was q13 done?

Also was is right to answer t100=t99 + t98 with:

T3 = t2 + t1
3=2+1
3=3

It says explain so they might have wanted more but I say you still got a big chunk of the marks at the very leastand for q)13 for a) you just moved the y value up 2 units and for b) you timesed it by minus 1 eg if the og line is at y=4 then b) is at y=-4

patrickLouth1

haiyna wrote: »

I got 3k+5=k
2k=-5
K=-5/2

I got the same thank you

gj kg hjjjj

Do you still get marks for the right answer without workings

Kbvdpo

james_jog99 wrote: »

It says explain so they might have wanted more but I say you still got a big chunk of the marks at the very leastand for q)13 for a) you just moved the y value up 2 units and for b) you timesed it by minus 1 eg if the og line is at y=4 then b) is at y=-4

Thanks!👍 I did write down a lot of words aswell, they made sense at the time but I don't remember what they were now!
Thanks, I think that's what I did but I wasn't sure if it was right!
Did you do the paper today? What did you think? I thought it was great! If paper 2 is going to be anything like then I'll be hoping for a good grade! Got a b in the mocks & they were far worse than that paper today!

bearwhite

For the last bit in question 14 I took a shot in the dark and said it was exponential...

UnknownEntity

Kbvdpo wrote:

Thanks!👠I did write down a lot of words aswell, they made sense at the time but I don't remember what they were now! Thanks, I think that's what I did but I wasn't sure if it was right! Did you do the paper today? What did you think? I thought it was great! If paper 2 is going to be anything like then I'll be hoping for a good grade! Got a b in the mocks & they were far worse than that paper today!

If paper 2 is ANYTHING like paper 1 then we will be one very lucky bunch indeed!

james_jog99

gj kg hjjjj wrote: »

Do you still get marks for the right answer without workings

Very little to none. The main focus of the exam is to see if you can find out how to do the question that's why attempt marks are a thing.