By interchanging the given two signs which of the following equation will be not correct?
- and ÷

Correct option is A

Do it by options: →
a) 20 × 8 – 4 ÷ 2 + 7 = 50
20 × 8 ÷ 4 – 2 + 7 = 50
=> 40 – 2 + 7 = 50
=> 45 ≠ 50 → not correct
b)
35 – 5 + 8 ÷ 4 × 3 = 3
35 ÷ 5 + 8 – 4 × 3 = 3
7 + 8 – 12 = 3
3 = 3 correct
c) 10 + 8 × 6 - 4 ÷ 2 = 20
10 + 8 × 6 ÷ 4 – 2 = 20
10 + 12 – 2 = 20
20 = 20 correct
d)
12 – 4 + 11 × 3 ÷ 8 = 28
12 ÷ 4 + 11 × 3 – 8 = 28
=> 3 + 33 – 8 = 28
Option (a) is not correct