SPM 2019 - P1 - Passcord Question (Permutation)

in this video, I will try to explain the questions base on my understanding. Not sure it is correct or not? But I hope you still find it helpful.

[wyn]

Sir you missed one critical info for the pass code one
1313 is counted twice
At 1 3 _ _ the space could also have 13
At _ _ 1 3 the space will also have 13, thus we counted 1313 twice
hence the true answer is 10^4 - 299 = 9701

[eternalbyzantium]

I swear you are going to be one of Malaysia most well known mathematics teacher. Start an online business already, take advantage of modern day opportunities. A man who can simplify yet sympathize with students who are immensely weak. A lifesaver for all. Good luck for the future Sir.

[JJFade]

Batch 02 SPM kinda messed up..like really messed up

[aidamohd]

hey you've upgraded your videos! I'm so proud that this channel is still ongoing and that you are still doing free tutorials on addmaths. I used to watch your videos to prepare for spm2016 and I just wanted to say thank you for your tutorials, for making addmaths easier and for making education easily accessible by everyone :) I wouldn't have gotten an A for addmaths in 2016 if it wasnt for you, thank you and bless you mr matthew. Good luck to everyone studying for exams and dont take medicine just because your parents told you to alright hahahaha

[Anand-ndhk]

addmath so hard but this teacher can still laugh while teaching

[asuka-ryo]

Anyway, I'm loving this new "format" of teaching!

[HoshikawaHikari]

Seriously, they need to make the question clear! I wasted time on that one and left it blank in the end

[willlee]

You have to keep cool don't press on the panic button. In this type of question spend more time on reading the question because solving them is very fast by using the calculator.
The examiner know that they themselves can't solve these type of question if it's not clear about the given constraints. Make sure it's HOT but really clear and don't put yourselves in HOT SOUP.

[asuka-ryo]

I really miss watching sir's videos so I can't wait to see you make a video on 2019's SPM Add Maths papers.

Till then, have a great New Year!

[skullz]

I see alot of these questions now in add maths books. They have this question alot most of the markingg schemes takes the “real world scenario” as the main answer and follow ur answer. I didnt get why it was always 299 but now i do thanks so much.

[marcuschai]

I didn’t even do that question?? I skipped it

[deliaclaudette]

lmao i cant relate i didn't even get to answer this. threw a bunch of numbers before time was up and just prayed for mercy

[carsonlim]

Sir 0131 is not fulfilled the condition it should be 1103

[lyndnn_]

Sir I think it is because of the word “reset”. It means you can just ignore the original passcode and solve the question using the real world scenario

[beanhwak]

I think 10000-100-100-99 =9701 because 1313 is counted subtracted in the cases 1x1x10x10 and 10x10x1x1 but not in 1x10x10x1

[inginjagomobilelegends]

some people do not understand the question. Fortunately I answered correctly. @02 gud luck kimia esok

[mohhaf]

To answer the 2nd method in a more untechnical way, just list the numbers and cancel whichever that do not fit the criteria

0113 - NO
0131 - NO
0113 - 2nd
0131 - 2nd
0311 - YES
0311 - 2nd
1013 - NO
1031 - YES
1103 - YES
1130 - NO
1301 - NO
1310 - NO
1013 - 2nd
1031 - 2nd
1103 - 2nd
1130
- 2nd
1301
- 2nd
1310 - 2nd
3011 - YES
3011 - 2nd
3101 - YES
3110 - YES
3101 - 2nd
3110 - 2nd

So the answers are 0311, 1031, 1103, 3011, 3101, 3110

[MathTutorEdu]

I hope after this, the examiner will set the paper and specify the constraints clearly to the students as this might confuses them during the examination.

[khookengsuen]

if you use the listing method, it should be 1103 instead of 0131, since you said it cannot be 1 followed by 3
0311
1103
1031
3110
3101
3011

[Blaze]

Man. My answer was 9699.. I calculated all possibilities with "13" inside and then got 300 possibilities. Then at the last 10 seconds my brain told me got one possibility which is "1313" that repeats twice but I forgot to take into account(Actually calculated it twice in 13XX and XX13) so should be 299 possibilities. But instead of:
10000 - (300-1) = 9701.. I did
10000 - 300 - 1 = 9699...
ggwp