Hope you like giving free advice here! Might be time to get out...

Hope you like giving free advice here! Might be time to get out the calculator..

I had 47 shares in RIO at $77, just before news of the rights issue came out. Thinking that you had to have exaclty 40 shares to get 21 more, would it have made sense to sell at $77 (ie sell 7 shares and get about $500) and then buy the new cheaper shares for the discount and hang on to them before selling at some kind of profit over the average price of the old shares? To me, even more profit, as I bought my old shares for $42.
The maths is fun but interspersed with that is when should I sell, when the rights issue actually starts (if I sell my 47 shares now, even tho the cheque is in the mail, do I still get my cheapies??) and basically it is juggling a whole bunch of balls in the air with dates on them.
Who among you thought of the same shenanigans..and did it?

I intend for BHP to eat RIO soon anyway, so am hanging on to them partly for that reason.

Many thanks, maths whizzes!