Correct Answer: 4 × 5 – 36 ÷ 6 + 10 = 10

Solution : Given:
– and ×

Replace the given signs in the options one by one with the original signs in the given equation.
First option: – and ×
20 × 12 + 6 – 16 ÷ 8 = 20
= 20 – 12 + 6 × 16 ÷ 8
= 8 + 12
= 20
Second option: – and ×
16 × 91 ÷ 13 + 5 – 3 = 24
= 16 – 91 ÷ 13 + 5 × 3
= 16 – 7 + 5 × 3
= 16 – 7 + 15
= 24
Third option: – and ×
20 × 8 – 4 ÷ 2 + 3 = 7
= 20 – 8 × 4 ÷ 2 + 3
= 20 – 16 + 3
= 7
Fourth option: – and ×
4 × 5 – 36 ÷ 6 + 10 = 10
= 4 – 5 × 36 ÷ 6 + 10
= 4 – 30 + 10
= – 16 ≠ 10

So, only in the fourth option L.H.S. ≠ R.H.S. of the given equation. Hence, the fourth option is correct.