Correct Answer: 9 and 6

Solution : Given:
108 ÷ 6 – 18 + 8 × 9 = 42

Replace the given numbers according to the options one by one with the original symbols in the given equation.
First option: 108 and 18
Solving the L.H.S. of the equation –
⇒ 18 ÷ 6 – 108 + 8 × 9
= 3 – 108 + 72
= –33 ≠ 42
Second option: 9 and 6
Solving the L.H.S. of the equation –
⇒ 108 ÷ 9 – 18 + 8 × 6
= 12 – 18 + 48
= 42 = 42
Third option: 18 and 9
Solving the L.H.S. of the equation –
⇒ 108 ÷ 6 – 9 + 8 × 18
= 18 – 9 + 144
= 153 ≠ 42
Fourth option: 6 and 8
Solving the L.H.S. of the equation –
⇒ 108 ÷ 8 – 18 + 6 × 9
= 13.5 – 18 + 54
= 49.5 ≠ 42

So, only the second option satisfies the R.H.S. of the given equation. Hence, the second option is correct.