How to calculate price of 1 share of m&m finance

Continuing the discussion from Everything you need to know about the M&M Financial rights issue:

ITS VERY SIMPLE TO ESTIMATE THE COST OF 1 SHARE .
COST OF ONE SHARE AT WHICH IT IS CLOSED ON 21/7 =ALMOST 227
NOW WE ARE GETTING 1 FOR 1 BUT THE EXTRA 1 SHARE IS OF COST =50
SO NEW PRICE OF 1 SHARE = (227+50) /2=277/2=138.50
I THINK WHEN IT OPEN ON 22/7 IT WAS ALMOST 136.
THANKS.