36 - [18 - {14 - (15 - 4 ÷ 2 × 2)}]. Simplify the expression.

Question: 36 - [18 - {14 - (15 - 4 ÷ 2 × 2)}]. Simplify the expression.

Solution:
36 - [18 - {14 - (15 - 4 ÷ 2 × 2)}]
= 36 - [18 - {14 - (15 - 2 × 2)}]
= 36 - [18 - {14 - (15 - 4)}]
= 36 - [18 - {14 - 11}]
= 36 - [18 - 3]
= 36 - 15
= 21