how much time does a boy spend in his school when he reaches at 9.50am and leaves from his school at 2.40pm?

we can rewrite 2:40 as 14:40

then we subtract,
14:40 - 9:50
since 40 is less than 50, we add an hour to it or 60 minutes, while we subtract 1 from 14:
13:100 - 9:50
4 : 50 = 4 hours and 50 minutes

hope this helps~ :)

4 hours and 50 minutes

To calculate the time a boy spends in school, we need to subtract the leaving time from the arrival time.

Step 1: Convert the arrival and leaving times into a 24-hour format for easier calculation.

The arrival time is 9:50 am, which is 09:50 in the 24-hour format.
The leaving time is 2:40 pm, which is 14:40 in the 24-hour format.

Step 2: Subtract the arrival time from the leaving time.

14:40 - 09:50 = 04:50 (in the format HH:MM)

Step 3: Convert the time difference back to hours and minutes.

04:50 is equivalent to 4 hours and 50 minutes.

Therefore, the boy spends 4 hours and 50 minutes in school from the time he arrives at 9:50 am until he leaves at 2:40 pm.