In 1 minute the copy machine copies = 24
That means
In 60 seconds the copy machine copies = 24
First we need to convert 5 minutes and 30 seconds to seconds
Then
5 minutes and 30 seconds = (5 * 60) + 30
= 300 + 30
= 330 seconds
So
In 330 seconds the copy machine will copy = (24/60) * 330
= 4 * 33
= 132
So in 5 minutes and 30 seconds the copy machine will copy 132 copies.
We use unit rate in every day life, for example, when comparing prices at stores. One store may offer five bowls for $7.99 and the other one bowl for $2.45.
Consider such events:
A - slip with number 3 is chosen;
B - the sum of numbers is 4.
You have to count 
Use formula for conditional probability:
1. The event 
consists in selecting two slips, first is 3 and second should be 1, because the sum is 4. The number of favorable outcomes is exactly 1 and the number of all possible outcomes is 5·4=20 (you have 5 ways to select 1st slip and 4 ways to select 2nd slip). Then the probability of event is
2. The event 
consists in selecting two slips with the sum 4. The number of favorable outcomes is exactly 2 (1st slip 3 and 2nd slip 1 or 1st slip 1 and 2nd slip 3) and the number of all possible outcomes is 5·4=20 (you have 5 ways to select 1st slip and 4 ways to select 2nd slip). Then the probability of event is
3. Then
Answer: 
