How much does each copybook cost if David pays $72.50 for 50 copybooks?

To determine the cost of each copybook, you need to divide the total amount paid by the number of copybooks purchased. In this case, David spent a total of $72.50 for 50 copybooks.

First, perform the division:

[

\text{Cost per copybook} = \frac{\text{Total cost}}{\text{Number of copybooks}} = \frac{72.50}{50}

]

Now, carry out the calculation:

[

\frac{72.50}{50} = 1.45

]

This means that each copybook costs $1.45. The correct answer reflects the accurate division of total cost by the number of items, leading to the understanding that the cost per unit is essential in real-world budgeting and expense tracking.