A boy went to the library;
he read a novel for an hour,
a scientific book for hour, and a newspaper for an hour.
How many minutes did he spend in the library?
Step 1: Convert hours to minutes.
For the novel: 1 hour = 60 minutes. We know that 20 minutes + 20 minutes + 20 minutes = 60 minutes, so of an hour = 20 minutes.
For the scientific book: 1 hour = 60 minutes.
For the newspaper: 1 hour = 60 minutes. We know that 15 minutes + 15 minutes + 15 minutes + 15 minutes = 60 minutes, so of an hour = 15 minutes.
Step 2: Add 20 minutes + 60 minutes + 15 minutes.
So, the boy spent 95 minutes at the library.