Suppose contact lenses cost $300 for a year’s supply or $30 for a month’s supply. Which is less expensive to order per year, paying for 12 months at one time or paying for 1 month at a time?(1 point)

Question

month(s) at a time

Give a simple and correct answer

Answer 1

To find out which option is less expensive per year, let's compare both options.

Paying for a year's supply at one time:
Cost per month = $300 / 12 months = $25 per month

Paying for a month's supply at one time:
Cost per month = $30

From the calculations above, we can see that paying for a year's supply at one time costs $25 per month, while paying for a month's supply at one time costs $30 per month.

Therefore, it is less expensive to order contact lenses by paying for 12 months at one time.

Answer 2

how many months at a time

Answer 3

To determine how many months at a time is less expensive, we need to compare the cost of different options.

Suppose we want to compare the cost of ordering contact lenses for n months at a time. The cost for a year's supply is $300, which is equivalent to ordering for 12 months at a time.

Thus, the cost for n months at a time can be calculated as follows:

Cost for n months = ($30 × n)

We need to find the value of n for which the cost for n months at a time is less than $300.

($30 × n) < $300

Dividing both sides by $30, we have:

n < $300 / $30

n < 10

This means that ordering contact lenses for fewer than 10 months at a time would be less expensive than ordering for a year's supply.