Correct Answer: 7 × 8 ÷ 4 + 2 – 6 = 49

Solution : Given:
Interchange + and ÷

First option: 18 + 6 – 6 ÷ 3 × 3 = 6
Interchanging + and ÷, and solving the L.H.S. we get,
18 ÷ 6 – 6 + 3 × 3
= 3 – 6 + 3 × 3
= 3 – 6 + 9
= 3 + 3
= 6 = R.H.S
Second option: 18 + 2 × 6 ÷ 3 – 7 = 50
Interchanging + and ÷, and solving the L.H.S. we get,
18 ÷ 2 × 6 + 3 – 7
= 9 × 6 + 3 – 7
= 54 + 3 – 7
= 57 – 7
= 50 = R.H.S
Third option: 7 × 8 ÷ 4 + 2 – 6 = 49
Interchanging + and ÷, and solving the L.H.S. we get,
7 × 8 + 4 ÷ 2 – 6
= 7 × 8 + 2 – 6
= 56 + 2 – 6
= 58 – 6
= 52 ≠ R.H.S
Fourth option: 6 × 9 + 3 – 24 ÷ 8 = 2
Interchanging + and ÷, and solving the L.H.S. we get,
6 × 9 ÷ 3 – 24 + 8
= 6 × 3 – 24 + 8
= 18 – 24 + 8
= – 6 + 8
= 2 = R.H.S

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