Answer:
You need to try and find the total cost of the food and drink and subtract it from the amount of money Simon pays.
Two cups of coffee costs 2.78 so -
2.78 + 2.78 = 5.56
One piece of cake costs 2.85 so the total amount is
5.56 + 2.85 = 8.41
Now we know the total, we can subtract it from the money given.
10 - 8.41 = 1.59
Simon will get 1.59 in change.
