Each player would have to sell 9 candles.
This can be found by adding $1,240 and $572. This gives you $1,812 which you'd subtract $786 (how much they already have) from $1,812 to get $1,026.
Next you'd multiply $9.50 by 12 (number of players) to get 114. Finally you divide 1,026 by 114, to get the number of candles (9).
I hope this helps!!