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JEE MATHEMATICS MCQ: PERMUTATIONS

1 Medium

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Application +4 | -1

If

{ }^{56} P_{r+6}:{ }^{54} P_{r+3}=30800: 1

, then the value of

r

is

View answer and explanation

Correct option: C

41

Option C (41) is correct because solving the equation

\frac{{ }^{56} P_{r+6}}{{ }^{54} P_{r+3}}=30800

for

r

gives

r=41

.

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