2. Find all positive integers $n$ such that $\phi(n)$ has the value
a) 1
d) 6
b) 2
e) 14
c) 3
f) 24 .
2. a) 1,2 b) $3,4,6$ c) no solution $\quad$ d) $7,9,14$, and 18 e) no solution
f) $35,39,45,52,56,70,72,78,84,90$