Correct Answer: ÷, –, ×, +

Solution : Given:
256 * 4 * 9 * 3 * 14 = 51

Let's check each option –
First option: ×, +, –, ÷
256 × 4 + 9 – 3 ÷ 14 = 51
L.H.S. = 256 × 4 + 9 – 3 ÷ 14
= 256 × 4 + 9 – 0.21
= 1024 + 9 – 0.21
= 1032.79 ≠ 51
Second option: ÷, ×, –, +
256 ÷ 4 × 9 – 3 + 14 = 51
L.H.S. = 256 ÷ 4 × 9 – 3 + 14
= 64 × 9 – 3 + 14
= 576 – 3 + 14
= 587 ≠ 51
Third option: ×, ÷, +, –
256 × 4 ÷ 9 + 3 – 14 = 51
L.H.S. = 256 × 4 ÷ 9 + 3 – 14
= 256 × 0.44 + 3 – 14
= 112.64 + 3 – 14
= 101.64 ≠ 51
Fourth option: ÷, –, ×, +
256 ÷ 4 – 9 × 3 + 14 = 51
L.H.S. = 256 ÷ 4 – 9 × 3 + 14
= 64 – 9 × 3 + 14
= 64 – 27 + 14
= 51 = R.H.S.

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