Okay, for these two questions I have the answers - but I can't figure out the process. HOW did they get these answers?

1. There are 132 members of the Volunteer Fire Dept. At a recent alarm, 1/4 of the volunteers responded. How many volunteers did NOT respond?

Answer: 99

2. It takes a machine 2 minutes and 15 seconds to assemble one chair. If the machine runs continuously for 6 hours, how many chairs will it produce?

Answer: 160

I need to know how to get these answers so that when I come to similar problems, I'll know. Thanks in advance.

2 answers

1.
1/4 * 132 = 33
132 - 33 = 99

2.
Since 15 seconds is 1/4 of a minute, first change 2 minutes and 15 seconds to 2 1/4 minutes. Then, let's find out how many chairs are assembled in 60 minutes (1 hour).

60 / 2 1/4 = 60 / 9/4 = 60 * 4/9
60 * 4/9 = 240/9 = 26 2/3

Multiply: 26 2/3 * 6 = 160
4/217