Reward, one week only, receive a 10 dollar gift card for every 50 dollars spent.

1) If your reward is $10, what do you know about the amount of your purchase?

2) Give three possible amounts if your reward is $20.

3) What should you do if your total purchase is $98? Explain your answer

If you received a $10 reward, then you spent between $50 and $99.99

If you received a $20 reward, then you could have spent $100, $125, or $149.99.
If your purchase is $98, then you'd be better off spending $2 more, so that you'll get another $10 gift card. That would be a net gain of $8, plus the other $10 gift card you got for the first $50 you spent.

1) If your reward is $10, you know that you have spent a multiple of $50 on your purchase. In other words, you have spent $50, $100, $150, and so on.

2) If your reward is $20, there are several possible amounts you could have spent to receive that reward. Here are three examples:
a) $100: You would have spent $100 and received two $10 rewards.
b) $150: You would have spent $150 and received three $10 rewards.
c) $250: You would have spent $250 and received five $10 rewards.

3) If your total purchase is $98, you would not qualify for a reward because you have not spent a multiple of $50. To receive a reward, you would need to spend at least $100, which would give you two $10 rewards. So in this case, you could consider adding more items to your purchase to reach the $100 threshold and become eligible for the rewards.