Correct Answer - Option 1 : 42
The logic followed is:
Two make the given code correct.
@ = +
# = ×
4 @ 9 # 6 = 58
Now replacing it,
4 + 9 × 6 = 58
4 + 54 = 58
58 = 58
5 @ 8 # 7 = 61
5 + 8 × 7 = 61
5 + 56 = 61
61 = 61
Similarly,
6 @ 12 # 3 = ?
6 + 12 × 3 = ?
6 + 36 = ?
? = 42
Hence, the correct answer is "42".