Permutations And Combinations Question 288
Question: If $ a $ denotes the number of permutations of $ x+2 $ things taken all at a time, $ b $ the number of permutations of $ x $ things taken 11 at a time and $ c $ the number of permutations of $ x-11 $ things taken all at a time such that $ a=182\ bc $ , then the value of $ x $ is
Options:
A) 15
B) 12
C) 10
D) 18
Correct Answer: B $ \Rightarrow \ (x+2)!\ =182x\ !\Rightarrow (x+2)(x+1)=182 $ $ \Rightarrow $ $ x=12 $ .
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Answer:
Solution:
BETA
