When subtracting like fractions, what happens to the numerator and the denominator?

What could explain what happened when the time was equal to 120 minutes

Acompany produces packets of soap powder labeled “giant size 32 ounces.” the actual weight of soap powder in such a box has a normal distribution with a mean of 33 oz and a standard deviation of 0.7 oz. to avoid having dissatisfied customers, the company says a box of soap is considered underweight if it weighs less than 32 oz. to avoid losing money, it labels the top 5% (the heaviest 5%) overweight. how heavy does a box have to be for it to be labeled overweight?

Including 6% sales tax, an inn charges $135.68 per night. find the inns nightly cost