[Question]: Todd has $20. He buys 4 candy bars that cost $2 each. How much money in dollars does Todd have left?
[Answer]: The candy bars cost 4 * 2 = $8. Todd has 20 - 8 = $12 left.
So the answer is 12.

[Question]: At school today, Charlize was 20 minutes late. Four of her classmates were each ten minutes late than she was. What's the total time for which the five students were late?
[Answer]: If Charlize was 20 minutes late, each of her friends was 20 + 10 = 30 minutes late. The total time for which Charlize's friends were late was 4 * 30 = 120 minutes. Together with Charlize, the three friends were 120 + 20 = 140 minutes late.
So the answer is 140.

[Question]: In a restaurant, one cup of coffee is $6 and a piece of cheesecake $10. When buying them together, the client gets a 25% discount. What is the final price of such a set?
[Answer]:
Both the cheesecake and coffee cost 10 + 6 = $16. The discount for these items is 25 / 100 * 16 = $4. So the final price for the cheesecake and coffee is 16 - 4 = $12.
So the answer is 12.