Question

Four friends bought books at a bookstore. The person who got the best deal has the lowest ratio of cost to number of books purchased.

Book Purchases
Name
Total Cost
Number of Books
Jo
$9
4
Kei
$12
8
Kate
$30
16
Bryn
$8
4

Who got the best deal?
Jo
Kei
Kate
Bryn

Answer 1

To determine who got the best deal, we need to calculate the cost per book for each person. The formula for cost per book is:

\[
\text{Cost per book} = \frac{\text{Total Cost}}{\text{Number of Books}}
\]

Now, let's calculate it for each friend:

1. **Jo**
- Total Cost: $9
- Number of Books: 4
- Cost per book: \(\frac{9}{4} = 2.25\)

2. **Kei**
- Total Cost: $12
- Number of Books: 8
- Cost per book: \(\frac{12}{8} = 1.5\)

3. **Kate**
- Total Cost: $30
- Number of Books: 16
- Cost per book: \(\frac{30}{16} = 1.875\)

4. **Bryn**
- Total Cost: $8
- Number of Books: 4
- Cost per book: \(\frac{8}{4} = 2.00\)

Now, let’s summarize the cost per book for each person:
- Jo: $2.25
- Kei: $1.50
- Kate: $1.875
- Bryn: $2.00

The person with the lowest cost per book (best deal) is Kei, with a cost of $1.50 per book.

Therefore, the answer is:
**Kei**