Correct Answer: +, –, ÷, ×, =

Solution : Given:
25 * 82 * 12 * 6 * 8 * 91

Replace the * sign given in the equation with the assigned signs in the options one by one –
First option: –, ×, +, ÷, =
25 – 82 × 12 + 6 ÷ 8 = 91
Solving the L.H.S. of the equation –
= 25 – 82 × 12 + 0.75
= 25 – 984 + 0.75
= –958.25 ≠ 91
Second option: ÷, +, –, ×, =
25 ÷ 82 + 12 – 6 × 8 = 91
Solving the L.H.S. of the equation –
= 0.304 + 12 – 6 × 8
= 0.304 + 12 – 48
= –35.696 ≠ 91
Third option: +, –, ÷, ×, =
25 + 82 – 12 ÷ 6 × 8 = 91
Solving the L.H.S. of the equation –
= 25 + 82 – 2 × 8
= 25 + 82 – 16
= 91
Fourth option: ×, +, ÷, –, =
25 × 82 + 12 ÷ 6 – 8 = 91
Solving the L.H.S. of the equation –
= 25 × 82 + 2 – 8
= 2050 + 2 – 8
= 2044 ≠ 91

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