2 Different way in calculating share for share offer

Dear tutor,

I can see there are 2 different way in calculating share for share offer between 2 question :
part c – Question 2 – Jun 2013 & part a – Question 3 – Dec 2012
In Jun 13 Q2, the offer is calculated by using current share price of Hav co. (Acquier) which is $9.64.
With 1 Hav co. ‘s share to 2 Strand co.’s share that means Strand co’s share is valued at $4.62 ($9.64 / 2 )
In contrast, in Dec 12 Q3, with the same deal as share for share exchange – 3 Sigra for 2 Dentro. The question also mentioned about the current share price of Sigra of $3.6 but the answer is differently calculated by using the combined company’s share price

I don’t understand the principle underlying in share for share exchange offer? or maybe i missed some clue in question?
Please explain for me why there are 2 way of quantifying the share for share exchange like that?

BR