Correct Answer: 3 and 6

Solution : Given:
43 ÷ 2 × 26 – 2 = 527

Let's check the options –
First option: 6 and 2
Since there are more than one 2's present in the equation, it is not clear which 2 needs to be interchanged. So, this option is incorrect.
Second option: 2 and 3
Since there are more than one 2's present in the equation, it is not clear which 2 needs to be interchanged. So, this option is incorrect.
Third option: 3 and 6
⇒ 46 ÷ 2 × 23 – 2 = 527
On solving the L.H.S. of the equation –
= 46 ÷ 2 × 23 – 2
= 23 × 23 – 2
= 527
Fourth option: 7 and 4
⇒ 73 ÷ 2 × 26 – 2 = 524
On solving the L.H.S. of the equation –
= 73 ÷ 2 × 26 – 2
= 36.5 × 26 – 2
= 949 – 2 = 947 ≠ 524

So, only the third option satisfies the equation. Hence, the third option is correct.