Answer:
16
Explanation:
When there are more than 1 brackets , there is a specific order of opening those brackets. First we open the bar , then round brackets , then curly brackets & then square brackets.
Using the order , let's solve this.
25-[20-{10-(7-5-3)}]
=> 25-[20-{10-(7 - 8)}]
=> 25-[20-{10 - (-1)}]
=> 25-[20- {10 + 1} ]
=> 25-[20 - {11}]
=> 25 - [ 20 - 11 ]
=> 25 - [9]
=> 25 - 9
=> 16