Answer:
$49
Explanation:
We have been given that Eric bought lunch for him and his friends at Papa's Pizza. His bill was $50 with tax. If he used a 15% off coupon and then left a 20% tip based on the discounted ticket.
First of all, we will find amount of bill after 15% discount by finding 85% of $50 as:
![\text{Bill after 15 percent discount}=\$50* (85)/(100)](https://img.qammunity.org/2020/formulas/mathematics/high-school/ox2x5128aiyo54uiuuayez481v4nx9x80y.png)
![\text{Bill after 15 percent discount}=\$50* 0.85](https://img.qammunity.org/2020/formulas/mathematics/high-school/d0zsut8x05ro8bg2eao6el4dc6rtgbkr1z.png)
![\text{Bill after 15 percent discount}=\$42.5](https://img.qammunity.org/2020/formulas/mathematics/high-school/ahbcel20c2lh6dotgm1ebd3ocg78aga1og.png)
Amount paid in tip would be 20% of $42.5, so total amount paid after 20% tip would be 42.5 plus 20% of $42.5.
![\text{Total amount of bill after tip}=\$42.5+\$42.5* (20)/(100)](https://img.qammunity.org/2020/formulas/mathematics/high-school/9tinsgxmv7giiq8jofy7kpd7pkenacx1z9.png)
![\text{Total amount of bill after tip}=\$42.5+\$8.5](https://img.qammunity.org/2020/formulas/mathematics/high-school/y86q7jr77d4hd2lf54acxmgl37nbon1m25.png)
![\text{Total amount of bill after tip}=\$51](https://img.qammunity.org/2020/formulas/mathematics/high-school/wv0gzjf95pgcb3l4thpytwq8qdpvfum4zb.png)
Now, we will subtract $51 from $100 to find amount of change that is
![\$100-\$51=\$49](https://img.qammunity.org/2020/formulas/mathematics/high-school/tl2xhp16wss1z4ynwzzi60g7qalshoe83q.png)
Therefore, Eric will get $49 in change.