Answer:
a
Dr Cash ($18 x 36,000 shares) Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â $ 648,000
Cr Common Stock  ($2 x 36,000 shares)        $72,000
Cr Share premium ($16,000 x 36,000 shares) Â Â Â $576,000
b
Dr Cash ($18 x 36,000 shares) Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â $648,000
Cr Common Stock  ($2 x 36,000 shares)           $ 72,000
Cr Share premium  ($16 x 36,000 shares)           $576,000
Explanation:
On both situations the journal entries remain the same.
The cash amount received of $648,000 shall be debited while the nominal values of the shares of $2 each shall be credited to the share capital account and the balance of $16 each shall be credited to share premium.