Which of the following is the least stable carbon free radical?

The stability of the following carbocations follows the order:
$I. (CH_3)_3C^{\oplus}$
$II. (CH_3)_2C^{\oplus}(OCH_3)$
$III. CH_3CH_2CH_2CH_2^{\oplus}$
$IV. CH_3CH^{\oplus}CH_2CH_3$

Among the following carbocations:
$(I)$ $Ph_{2}\stackrel{+}{C} CH_{2} Me$
$(II)$ $Ph CH_{2} CH_{2} \stackrel{+}{C} HPh$
$(III)$ $Ph_{2} CH \stackrel{+}{C} HMe$
$(IV)$ $Ph_{2} C(Me) \stackrel{+}{C} H_{2}$
The order of stability is:

The stable carbocation formed in the reaction of benzene with $n$-propyl chloride in the presence of anhydrous $AlCl_3$ is:

Arrange the following free radicals in the correct order of their stability:
$(i)$ $CH_2=\dot{C}H$
$(ii)$ $\dot{C}H_3$
$(iii)$ $CH_3-\dot{C}H-CH_3$
$(iv)$ $(CH_3)_3\dot{C}$

In which pairs,the first ion is more stable than the second?