alone it takes kai 10 hours to complete a one-hour long presentation. it takes ted 8 hours to complete a one hour long presentation. using a rational equation, how long would it take them to complete a one hour long presentation if they worked together

1 answer

Let's assume x is the time it would take them to complete a one-hour long presentation if they worked together.

Kai completes 1/10 of the presentation per hour (since he takes 10 hours to complete a one-hour presentation).
Ted completes 1/8 of the presentation per hour (since he takes 8 hours to complete a one-hour presentation).

Working together, Kai and Ted would complete 1/x of the presentation per hour.

According to the problem, Kai and Ted working together equals the sum of their individual work rates:

1/10 + 1/8 = 1/x

To find the common denominator, we multiply 10 and 8:
8/80 + 10/80 = 1/x

18/80 = 1/x

Now, we can cross-multiply to solve for x:

18x = 80

x = 80/18

x ≈ 4.44

Therefore, it would take them approximately 4.44 hours to complete a one-hour long presentation if they worked together.