Answer: $60
Explanation:
Let the total price of Zoe dinner = x
According to question,
He paid 11 % sales tax 20% on tip.
Therefore, he paid total extra charge = 11 + 20 = 31 %
That is, he paid 31 % extra in sales tax and tips for dinner.
But again according to the question,
Zoe paid $18.60 in sales tax and tips for her dinner.
⇒ 31 % of x = 18.60
⇒
⇒
⇒
⇒ x = 60
Thus, The total cost of Zoe's dinner before tax = $60