Correct Answer: ÷, ×, +, =, +

Solution : Given:
42 * 7 * 3 * 2 * 13 * 7

Replace * with the mathematical signs and solve the equations one by one using BODMAS.
First option: ÷, ×, −, =, ×
42 ÷ 7 × 3 − 2 = 13 × 7
L.H.S. = 42 ÷ 7 × 3 − 2 = 6 × 3 − 2 = 18 − 2 = 16
R.H.S. = 13 × 7 = 91
L.H.S. ≠ R.H.S.
Second option: +, =, ÷, ×, +
42 + 7 = 3 ÷ 2 × 13 + 7
L.H.S. = 42 + 7 = 49
R.H.S. = 3 ÷ 2 × 13 + 7 = 1.5 × 13 + 7 = 19.5 + 7 = 26.5
L.H.S. ≠ R.H.S.
Third option: ÷, ×, =, +, +
42 ÷ 7 × 3 = 2 + 13 + 7
L.H.S. = 42 ÷ 7 × 3 = 6 × 3 = 18
R.H.S. = 2 + 13 + 7 = 22
L.H.S. ≠ R.H.S.
Fourth option: ÷, ×, +, =, +
42 ÷ 7 × 3 + 2 = 13 + 7
L.H.S. = 42 ÷ 7 × 3 + 2 = 6 × 3 + 2 = 18 + 2 = 20
R.H.S. = 13 + 7 = 20
L.H.S. = R.H.S.

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