Question Detail

STA 112 PERMUTATIONS AND COMBINATIONS Objective Question
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Question

If 12C5 = 12Cr, then what is the value of r?
Options
A 5
B 7
C Both A and B
Correct Answer
D 12
Correct Answer

Option C is the correct answer.

Detailed Explanation

The property of combinations states that if nCx = nCy, then either x = y or x + y = n. In this case, 12C5 = 12Cr, so either r = 5 or r + 5 = 12. If r + 5 = 12, then r = 12 - 5 = 7. Therefore, r can be either 5 or 7.

Hint

Recall the property of combinations: nCr = nCn-r.

Question Info

Course: STA 112
Topic: PERMUTATIONS AND COMBINATIONS
Type: Objective
Difficulty: Not specified
Question 72 of 112
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