The Jayden family eats at a restaurant that is having a 15% discount promotion. Their meal cost $78.65, and they leave a 20% tip. of the tip applies to the cost of the meal before the discount, what is the total cost of the meal?

The 15% discount means that they only pay 100%-15% = 85% of the meal's bill.

This would cost 85% * 78.65.

However, they also have to pay a 20% tip of the meal cost.

This would cost 20% * 78.65.

Total Cost = (85% * 78.65) + (20% * 78.65)

= 105% * 78.65

= 1.05 * 78.65

= $82.58