Answer:
She saved $7.5 using coupon
Explanation:
The bill of restaurant is $ 50
We are given that Natalia wants to tip the server 20% of the original bill
So, Amount of tip =

Amount of tip =

Amount of tip = 10
So, Total amount = 50+10=$60
We are also given that she has a 15% off coupon
So, Amount saved using coupon =

So, she saved $7.5 using coupon