Correct Answer: +, ×, –, =

Solution : Given:
20 * 2 * 50 * 5 * 115

Replace the * sign given in the equation with the assigned signs in the options one by one –
First option: –, ×, =, +
20 – 2 × 50 = 5 + 115
L.H.S.→20 – 2 × 50
= 20 – 100 = –80
R.H.S.→5 + 115 = 120
L.H.S. ≠ R.H.S.
Second option: +, ×, =, –
20 + 2 × 50 = 5 – 115
L.H.S.→20 + 2 × 50
= 20 + 100 = 120
R.H.S.→5 – 115 = –110
L.H.S. ≠ R.H.S.
Third option: +, ×, –, =
20 + 2 × 50 – 5 = 115
L.H.S.→20 + 2 × 50 – 5
= 20 + 100 – 5 = 115
R.H.S.→115
L.H.S. = R.H.S.
Fourth option: –, ×, +, =
20 – 2 × 50 + 5 = 115
L.H.S.→20 – 2 × 50 + 5
= 20 – 100 + 5
= –75
R.H.S.→115
L.H.S. ≠ R.H.S.

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