Q. The number of elements in $P [P (P (ϕ))]$ is

1201 140 Sets Report Error

A

2

28%

B

3

24%

C

4

45%

D

5

3%

Solution:

$n [P (ϕ)] = 2^{0} = 1 [∵ n (ϕ) = 0]$
$n [P (P (ϕ))] = 2^{1} = 2$
$n [P {P (P (ϕ)}] = 2^{2} = 4$