Correct Answer: 5 and 6

Solution : Given:
8 ÷ 2 × 6 − 11 + 5 = 15

Let's check each option –
First Option: 2 and 8
On interchanging the numbers, we get –
2 ÷ 8 × 6 − 11 + 5 = 15
On solving the L.H.S. of the equation –
= 2 ÷ 8 × 6 − 11 + 5
= 1.5 − 11 + 5
= –4.5 ≠ 15
Second Option: 5 and 6
On interchanging the numbers, we get –
8 ÷ 2 × 5 − 11 + 6 = 15
On solving the L.H.S. of the equation –
= 8 ÷ 2 × 5 − 11 + 6
= 4 × 5 − 11 + 6
= 20 − 11 + 6
= 15
Third Option: 2 and 6
On interchanging the numbers, we get –
8 ÷ 6 × 2 − 11 + 5 = 15
On solving the L.H.S. of the equation –
= 8 ÷ 6 × 2 − 11 + 5
= 2.67 − 11 + 5
= –3.33 ≠ 15
Fourth Option: 6 and 11
On interchanging the numbers, we get –
8 ÷ 2 × 11 − 6 + 5 = 15
On solving the L.H.S. of the equation –
= 8 ÷ 2 × 11 − 6 + 5
= 4 × 11 − 6 + 5
= 44 − 6 + 5
= 43 ≠ 15

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