Correct Answer: 6 and 8

Solution : Given:
6 ² – 20 + (28 ÷ 7) – [(√4) × 8 ] + 2 ² = 40

Interchange the numbers according to the given options.
Let's check each option –
First option: 6 and 8
8 ² – 20 + (28 ÷ 7) – [(√4) × 6 ] + 2 ² = 40
= 44 + 4 – [2 × 6 ] + 4
= 48 – 12 + 4
= 40
Second option: 7 and 2
6 ² – 20 + (28 ÷ 2) – [(√4) × 8 ] + 7 ² = 40
= 16 + 14 – 16 + 49
= 63 ≠ 40
Third option: 2 and 8
6 ² – 20 + (28 ÷ 7) – [(√4) × 2 ] + 8 ² = 40
= 16 + 4 – 4 + 64
= 80 ≠ 40
Fourth option: 20 and 8
6 ² – 8 + (28 ÷ 7) – [(√4) × 20 ] + 2 ² = 40
= 28 + 4 – 40 + 4
= – 4 ≠ 40

Therefore, only the first option satisfies the R. H.S. of the equation. Hence, the first option is correct.