Paper 42 (13th May) - Full Solutions

[notnek01]

1 mark.. because they wanted simplest form!

Finally got access to the paper and I would like to thank you a lot sir for this! I wanted to ask you these questions:
If we calculate minor arc how many marks will I lose? i remember my answer was 19 something...
For the probability thing, probability of wearing gloves was 7/10 so not wearing gloves will be 3/10... so i did P(no hat, no scarf, no gloves) = 5/8 * 5/6 * 3/10 isn't this correct? :/
for the speed of water i got 1.74 cm/min and not 1740 how many marks will be deducted?
for finding OP3 i used similarity and pythagoras theorem but my answer was 2.07 something
and lol i had no clue at all for calculating n i just wrote crazy numbers!
Thanks a lot sir!

Minor arc: Probably 1 mark, maybe 2.

3/10 is the probability of no gloves if a hat and scarf are worn (the branch under 7/10). This is not the same as the bottom branch.

You won't get any marks for 1.74. You may get marks for working.

Again, no marks for 2.07 but maybe marks for working.

 

[notnek01]

in question 4d) if i multiply by 2 how much will i get?

1 mark but maybe 2.

 

[Fabienne]

Thanks so much!
I just have one question, for the rotation 90° anti-clockwise about (0,0), I rotated it about a wrong point. Will that cost me all of my marks on that question?

 

[notnek01]

Sir, for the question by transformation by matrix, you sure its 90 anticlockwise? I multiplied 2 matrices I got it 90 clockwise

Yes, I'm sure.

 

[wajeehaz]

9ai. If you added 2*(your hexagon area) to the correct rectangles area then I think you'll get 2 marks.

9bii. I'm really not sure here. I was surprised it was a 5 mark question so I don't know how the marks will be given.

no, for the area of hexagon i did 4x6 and then multiplied answer by two..later i added this ans with the rectangle one
for 9bi) i used speed=distance/time but i didnt covert the litres, will i get any marks?

 

[notnek01]

sir can u like upload it again or something.. couz its like the file is damaged?

No one else is having a problem. Maybe try a different computer?

 

[notnek01]

Hello. For question 9 b I used 12 instead of 12000 in both sections. However all the steps are correct. How much will I get out of 9 ?

At least 2 maybe 3.

 

[notnek01]

Thanks so much!
I just have one question, for the rotation 90° anti-clockwise about (0,0), I rotated it about a wrong point. Will that cost me all of my marks on that question?

I'm not sure about this, sorry.

 

[notnek01]

no, for the area of hexagon i did 4x6 and then multiplied answer by two..later i added this ans with the rectangle one
for 9bi) i used speed=distance/time but i didnt covert the litres, will i get any marks?

Hexagon question: maybe 2 marks?

bi. If the rest of your working is correct, you'll get at least 2 maybe 3.

 

[Princess Raven]

ok it finally opened!! btw sir for 7aiii u didnt u write it in the form of a matrix?

 

[Ebby_SaLeem]

Minor arc: Probably 1 mark, maybe 2.

3/10 is the probability of no gloves if a hat and scarf are worn (the branch under 7/10). This is not the same as the bottom branch.

You won't get any marks for 1.74. You may get marks for working.

Again, no marks for 2.07 but maybe marks for working.

If so is the case then I'm getting exactly 176/200 which is an 88%! <3
Thanks sir!

 

[M.A.H]

Yes, I'm sure.

If there is no problem or wastage of your time sir, may you please post a multiplication of this matrix by the matrix from the shape we already have? I'm almost sure I multiplied but got a different answer.

And If I did it wrong, like rotation in opposite direction, will I lose all the marks?

Thanks in advance.

 

[Nbl_Amd]

Approximate 190/200 alhumdullillah Expecting A*

 

[Ratatat]

ok it finally opened!! btw sir for 7aiii u didnt u write it in the form of a matrix?

(2) is a 1 x 1 matrix.

 

[vinod]

sir how shud we get other subjects paper?

 

[notnek01]

ok it finally opened!! btw sir for 7aiii u didnt u write it in the form of a matrix?

Yes I did. (2) is a 1x1 matrix containing the entry 2.

 

[notnek01]

If there is no problem or wastage of your time sir, may you please post a multiplication of this matrix by the matrix from the shape we already have? I'm almost sure I multiplied but got a different answer.

And If I did it wrong, like rotation in opposite direction, will I lose all the marks?

Thanks in advance.

I would prefer it if you post your working and I will correct it.

 

[aaaamfa]

24 hours have passed so here are full solutions to the 13th May IGCSE Maths Paper 42. These are my (IGCSE maths teacher) solutions and not the official solutions from CIE.

I’ll try to answer any questions regarding this paper but...

Since I don’t want to make any predictions that could be wrong, I will not answer any questions like, 'What will I need to get this grade?' or 'How hard/easy was the paper, what will the A boundary be?'.

I’ll only say that I thought it was a very hard paper, one of the hardest in recent years.

Here are the average total grade boundaries over the last 2 years:

A* : 174.7/200
A : 145.6/200
B : 114.8/200
C : 84.4/200

You can see my solutions to Paper 22 here.

sir what if i wrote 184.5-100 to give the percentage profit in 1d how many marks am i doing to loose

 

[notnek01]

sir what if i wrote 184.5-100 to give the percentage profit in 1d how many marks am i doing to loose

You will get no marks for your answer but may get marks for your working.

 

[Princess Raven]

sir in the speed question if we wrote.. 1743.8 will they minus a mark? and if we write 87.4?