Correct Answer: ×, –, ÷, +

Solution : Given:
21 * 4 * 156 * 13 * 11 = 83

Replace * with the mathematical signs and solve the equation using BODMAS.
Let's check the given options –
First option: –, ÷, ×, +
⇒ 21 – 4 ÷ 156 × 13 + 11 = 83
Solving L.H.S. of the equation –
= 21 – 0.025 × 13 + 11
= 21 – 0.34 + 11
= 32 – 0.325
= 31.67 ≠ 83
Second option: ×, +, ÷, –
⇒ 21 × 4 + 156 ÷ 13 – 11 = 83
Solving L.H.S. of the equation –
= 21 × 4 + 12 – 11
= 84 + 12 – 11
= 96 – 11
= 85 ≠ 83
Third option: ×, –, ÷, +
⇒ 21 × 4 – 156 ÷ 13 + 11 = 83
Solving L.H.S. of the equation –
= 21 × 4 – 12 + 11
= 84 – 12 + 11
= 95 – 12
= 83
Fourth option: +, ÷, –, ×
⇒ 21 + 4 ÷ 156 – 13 × 11 = 83
Solving L.H.S. of the equation –
= 21 + 0.025 – 13 × 11
= 21 + 0.025 – 143
= 21.025 – 143
= –121.975 ≠ 83

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