Question

The students of grade 9ab were told that the class will start at 8:30 am. If it started at 9:11 am, how many minutes late was this student?

A) 31 minutes late
B) 41 minutes late
C) 51 minutes late
D) 21 minutes late

Answer 1

By subtracting the scheduled class time from the actual start time and adjusting for the overcalculated minutes, we determine the student was 31 minutes late to class.

Step-by-step explanation:

To calculate how many minutes late the student was, we subtract the scheduled start time of the class from the actual start time. The class was supposed to start at 8:30 am and actually started at 9:11 am.

First, we count the full hour from 8:30 am to 9:30 am, which is 60 minutes. But since the class started at 9:11 am, we need to subtract the 11 minutes that have passed in the hour after 9:00 am. So, we take 60 minutes and subtract 11 minutes, resulting in 49 minutes late.

However, since we must only account for the time until the class started, which was 9:11 am, we need to subtract an additional 19 minutes (from 9:11 to 9:30), as we've initially made a full hour calculation. This leaves us with 31 minutes late as the correct answer.