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JEE MATHEMATICS MCQ: PERMUTATIONS

1 Easy

1 of 1

Application +4 | -1

Let

f(n)

denotes the number of different ways the positive integer

n

can be expressed as the sum of 1's and 2's. For example

f(4)=5

, since

4=1+1+1+1,1+1+2,1+2+1,2+1+1,2+2

(Note Order of 1's and 2's is important). Then,

f\{f(6)\}

is

View answer and explanation

Correct option: C

f(13)

Option C (

f(13)

) is correct because

f(6)

is calculated to be 13, and therefore

f(f(6)) = f(13)

.

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