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Tamil Nadu Board of Secondary EducationHSC Science Class 11

Four children are running a race:In how many ways can the first two places be filled? - Mathematics

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Question

Four children are running a race:
In how many ways can the first two places be filled?

Sum
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Solution

Number of children in the running race = 4

The first place can be filled in (from the 4 children) 4 ways

After filling in the first place only 3 children are left out

So the second place can be filled in (from the remaining 3 children) 3 ways

So the first and the second places together can be filled in 4 × 3 = 12 ways

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Chapter 4: Combinatorics and Mathematical Induction - Exercise 4.1 [Page 166]

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Samacheer Kalvi Mathematics - Volume 1 and 2 [English] Class 11 TN Board
Chapter 4 Combinatorics and Mathematical Induction
Exercise 4.1 | Q 3. (i) | Page 166

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