Racehorse TALK

A question with fractional betting just introduced by UNiTAB

 Taking a box tri  under the old system 7 @$1 costs $210(7x6x5) if there's a late scratching you would be entitled to a refund in this  case of $90 having only 6 runners going (6x5x4=$120)

Now with fractional betting the cost is the same 7 original runners  $210 =100% and the late scratching reduces the combinations the same as before but does the late scratching result in a refund or if the tri gets up is the divvie increased from 100% to 252%

That's what I would like to know.  Any answers?