Welcome to Westonci.ca, your go-to destination for finding answers to all your questions. Join our expert community today! Our platform connects you with professionals ready to provide precise answers to all your questions in various areas of expertise. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

At a clockmaker's shop, the purchases for one month are recorded in the table below:

| | Remodel | Repair | New Purchase |
|---------------|---------|--------|--------------|
| Watch | 73 | 47 | 19 |
| Clock | 61 | 59 | 11 |
| Alarm Clock | 83 | 41 | 17 |

If we choose a customer at random, what is the probability that they have purchased an alarm clock or a new purchase?

[tex]\[ P(\text{Alarm Clock or New Purchase}) = \frac{57}{?} \][/tex]

Give your answer in simplest form.


Sagot :

To determine the probability that a randomly chosen customer has purchased an alarm clock or made a new purchase, we need to follow several steps:

1. Calculate the total number of customers:

We will sum up all the given values for each category:
- Watch: [tex]\(73 + 47 + 19 = 139\)[/tex]
- Clock: [tex]\(61 + 59 + 11 = 131\)[/tex]
- Alarm Clock: [tex]\(83 + 41 + 17 = 141\)[/tex]

So, the total number of customers is:
[tex]\[ 139 + 131 + 141 = 411 \][/tex]

2. Calculate the total number of customers who purchased an alarm clock:

Customers who purchased an alarm clock fall into all three categories (Remodel, Repair, New Purchase):
[tex]\[ 83 + 41 + 17 = 141 \][/tex]

3. Calculate the total number of customers who made a new purchase:

Customers who made a new purchase fall into each type of clock (Watch, Clock, Alarm Clock):
[tex]\[ 19 + 11 + 17 = 47 \][/tex]

4. Calculate the overlap between customers who made a new purchase and those who purchased an alarm clock:

Specifically, these are the customers who made a new purchase of an alarm clock, which is:
[tex]\[ 17 \][/tex]

5. Calculate the total number of customers who purchased an alarm clock or made a new purchase:

Since the customers who made a new purchase of an alarm clock are counted in both categories, we need to subtract this overlap once:
[tex]\[ 141 + 47 - 17 = 171 \][/tex]

6. Calculate the probability:

The number of favorable outcomes (customers who either purchased an alarm clock or made a new purchase) is [tex]\(171\)[/tex], out of a total of [tex]\(411\)[/tex] customers.

Therefore, the probability is:
[tex]\[ P(\text{Alarm Clock or New Purchase}) = \frac{171}{411} \][/tex]

7. Simplify the fraction to its simplest form:

Both [tex]\(171\)[/tex] and [tex]\(411\)[/tex] can be simplified by finding their greatest common divisor (GCD). The GCD of [tex]\(171\)[/tex] and [tex]\(411\)[/tex] is [tex]\(3\)[/tex]. So, we simplify the fraction:
[tex]\[ \frac{171 \div 3}{411 \div 3} = \frac{57}{137} \][/tex]

Thus, the probability that a randomly chosen customer has purchased an alarm clock or made a new purchase is:
[tex]\[ P(\text{Alarm Clock or New Purchase}) = \frac{57}{137} \][/tex]