GD Joshi is a teacher trainer, researcher and ICT consultant in Nepal. He is known for his innovative work in mathematics and Mathematics Education. Actually, his name is GhanShyam Joshi. People call him GD Joshi, GD stands for Ghan Shyam Datt. Thanks!

1. Permutation and Combination
Mathematics Guest Lecture By GD Joshi
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Notation for Permutation and Combination

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7. Let’s Understand More
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10. Let’s Understand More
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11. Role of Order in Different Situation
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13. Three Questions, Concept for Connecting Ideas
1) In how many ways can two persons sit in two
chairs?
2) In how many ways, can 4 digits be filled up in 3
places?
3) How many numbers of 4 digits can be formed
from the digits 4,5,6,7,8,9 which should be exactly
divisible by 2?
By basic principle of counting, it is 3×5×4×3=180
Equivalent to, 3 × P(5,3)
It tells that there are 3 choices for once place and
remaining 3 places can be filled up by 3 digits, which I
also 180 and same as above.
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1)
P(2
,2)
=
2!
2)
P(4
,3)
=4!/1!

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15. Clue Words of Permutation and Combination
Permutation
-Arrangement
-Schedule
-Order
-Line up
-Arrange
Note:These are for
lists.
Combination
-Group
-Sample
-Selection
-Choose
-Select
-Pick
Note:There are
for selection.
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17. Determining a question is of Permutation
or Combination
If the problem says " find in how many ways can they be
Arranged / Lined Up, made, ...."
then it is a problem on Permutations.
If the problem says " find in how many ways can it/they be
Selected / Chosen / Drawn / Taken/ grouped......"
then, it is a problem on Combinations.
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