The customers find an alternative holiday in Greece costing £1800, for them both, before discounts.
To calculate the cost of the holiday after the 20% incentive discount has been applied, we need to first determine the total value of the incentive.
We can do this by multiplying the original cost of the holiday (£1200) by 20% (0.20).
£1200 x 0.20 = £240
So the incentive is worth £240.
Now we can subtract this amount from the cost of the new holiday to find the final cost.
£1800 - £240 = £1560
So the final cost of the holiday in Greece after the 20% incentive discount has been applied is £1560.