Answer:
He paid $ 21.6 for the haircut.
Explanation:
Given,
The amount charged by hair stylist = $ 18,
The percentage of tip = 20 %,
So, the amount of the tip = 20 % of 18
= 0.2 × 18
= $ 3.6,
Hence, the total amount paid by him for haircut = The amount charged by hair stylist + Tip
= $ 18 + $ 3.6
= $ 21.6