Small quick qn from examworld.
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http://4.bp.blogspot.com/_MpWUhDNsH98/SP9LxxH3pgI/AAAAAAAAAbU/L5c87L1l6fs/s1600-h/circle2.gif
(iii) ∡BDC = ∡DBA - ∡BTD (exterior angle = sum of 2 interior angles)
∡BDC = 48° - 30°
∡BDC = 18°I dont understand this reasoning. what is exterior angle = sum of 2 interior angles? I hope it isnt in syllabus.
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one exterior angle of a triangle is twice the sum of two opposite interior angles lah.
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wa seh i still cant see where is the exterior angle man. The ext angle is more than 90 right?
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This is not the exterior angle of a polygon lah. This is the exterior angle of a triangle lor. So, the exterior angle of a triangle can be more 90 degrees hor.
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Ok firstly it has to be the toughest of luck that someone wld be able to help me here. I will check this first thing in the morning if someone has spotted my qn XD. Exam is at 8am XD
(2) Three unbiased dice are thrown.
Find the probability that
(i) they all show different numbersPls show working and explain how you did it. Reason i asked is because i dont understand the answer key.
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Originally posted by davidche:
Ok firstly it has to be the toughest of luck that someone wld be able to help me here. I will check this first thing in the morning if someone has spotted my qn XD. Exam is at 8am XD
(2) Three unbiased dice are thrown.
Find the probability that
(i) they all show different numbersPls show working and explain how you did it. Reason i asked is because i dont understand the answer key.
this is a nov 2002 Paper 1 Q16 question
I edited the solution in ExamWorld... Hopefully it's clearer now
(2)
(i) P(all different numbers) = P(first 2 dice are different and 3rd dice is also different number)= P(first 2 dice different) * P(3rd dice different number from first 2 dice)
= 5/6 * 4/6 (4 numbers out of 6 left since the first 2 dice have already taken/used up 2 numbers)
= 5/9For those who want to see the full question, do visit
http://examworld.blogspot.com/2008/10/o-lvl-em-probability_09.html -
Originally posted by davidche:
Ok firstly it has to be the toughest of luck that someone wld be able to help me here. I will check this first thing in the morning if someone has spotted my qn XD. Exam is at 8am XD
(2) Three unbiased dice are thrown.
Find the probability that
(i) they all show different numbersPls show working and explain how you did it. Reason i asked is because i dont understand the answer key.
nah, mine is too tedious
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A bag contains 7 black balls and 1 white ball. A second bag contains 6 black balls. Three balls are taken at random from the first bag and placed in the second bag. Find the probability that the white ball is now
(a) in the first bag
(b) in the second bag
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first step: ignore bag 2.
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Originally posted by skythewood:
nah, mine is too tedious
Good example of a question which TS should have posted the entire question instead of just this portion.
As per guidelines
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Originally posted by Lee012lee:
A bag contains 7 black balls and 1 white ball. A second bag contains 6 black balls. Three balls are taken at random from the first bag and placed in the second bag. Find the probability that the white ball is now
(a) in the first bag
(b) in the second bag
(a) Means all black balls chosen
Probability = 7/8 * 6/7 * 5/6 = 5/8(b) probability = 1 - 5/8 = 3/8
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Originally posted by davidche:
http://4.bp.blogspot.com/_MpWUhDNsH98/SP9LxxH3pgI/AAAAAAAAAbU/L5c87L1l6fs/s1600-h/circle2.gif
(iii) ∡BDC = ∡DBA - ∡BTD (exterior angle = sum of 2 interior angles)
∡BDC = 48° - 30°
∡BDC = 18°I dont understand this reasoning. what is exterior angle = sum of 2 interior angles? I hope it isnt in syllabus.
This topic already came out in paper 1.
I suggest you make sure instead you know the following topics...
1. Everyday Maths
2. Algebra Word Problem
3. Graph plotting
4. Trigonometry (sin/cos rules, shortest distance/angle of elevation)
5. Mensuration
6. Geometric Properties of Circles
7. Statistics (sd, histogram, cumulative)
8. Number Patterns
9. Probability
10. I don't know.
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Originally posted by Mikethm:
This topic already came out in paper 1.
I suggest you make sure instead you know the following topics...
1. Everyday Maths
2. Algebra Word Problem
3. Graph plotting
4. Trigonometry (sin/cos rules, shortest distance/angle of elevation)
5. Mensuration
6. Geometric Properties of Circles
7. Statistics (sd, histogram, cumulative)
8. Number Patterns
9. Probability
10. I don't know.
i tot tat is counted as circle properties.
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standard deviation.. dont forget leh
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This topic already came out in paper 1.
I suggest you make sure instead you know the following topics...
1. Everyday Maths - percentage and interest eh. easy.
2. Algebra Word Problem -easy
3. Graph plotting -use calculater and improvise. reciprocal and exponential graf i roughly know.
4. Trigonometry (sin/cos rules, shortest distance/angle of elevation) - yeap i learnt.
5. Mensuration -formula in the cover page
6. Geometric Properties of Circles - angles in semi circle, tangent and radius at P = 90 , agles in same seg, angle at centre = 2 angle at circumference, opp angles in cyclic quad = 180
7. Statistics (sd, histogram, cumulative) - sd-calc histo is bar. cumulative must know how to comment.- higher mean means higher score overal. higher sd or quatile range means higher spread in marks.
8. Number Patterns - i did this last night for 3 hours!!
9. Probability - exam world!! eagle rox
10. I don't know. - draw graph
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remember this when you need to calculate perpendicular distance for triangle
0.5 a b sin c = 0.5 * base * height
not much time to further explain
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both formulas can calculate for area. i see. insightful thanks. btw common base will come out. like ratio of this against another triangle XD.
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i must thank Mikethm because when he listed out those topics it gave me great confidence since i know what wld be coming out and that i know all those stuffs.