27/6 - 15: (1/8 - 1/4)

1. Simplify the expression in the parenthesis: 1/8 - 1/4 = 1/8 - 2/8 = -1/8.
2. Perform the division: 15 / (-1/8) = 15 * (-8) = -120.
3. Perform the subtraction: 27/6 - (-120) = 27/6 + 120 = 4.5 + 120 = 124.5.