Questions: A school board is proposing a 5% decrease in the length of the school day. Currently, the school day is 7 hours (420 minutes) long. How many minutes shorter would the school day be with the proposed decrease?

Solution Steps

To find the number of minutes shorter the school day would be with a 5% decrease, we need to calculate 5% of the current school day length (420 minutes) and then subtract that from the current length.

To find the decrease in the length of the school day, we calculate \( 5\% \) of \( 420 \) minutes: \[ \text{decrease amount} = \frac{5}{100} \times 420 = 21 \text{ minutes} \]

Next, we subtract the decrease amount from the current length of the school day: \[ \text{new length} = 420 - 21 = 399 \text{ minutes} \]

The difference in minutes, which represents how much shorter the school day would be, is equal to the decrease amount: \[ \text{difference in minutes} = 21 \text{ minutes} \]

Final Answer