The number 34613000 when expressed in exponential form is equal to

1. 3461.3 x 10³
2. 3.4613 x 10⁷
3. 0.34613 x 10⁹
4. 34.613 x 10⁵

Which is larger ?

(i) 2³ or 3²

(ii) 2⁵ or 5²

(iii) 3⁷ or 7³.