Question

there are 810 dishes that need to be rinsed. milan can rinse them in 90 minutes by himself. it will take his friend kevin 135 minutes to rinse these dishes. how long will it take them if they rinse these 810 dishes together?
minutes

Explanation:

Step1: Find work rates

Milan's rate: $\frac{810}{90} = 9$ dishes per minute.
Kevin's rate: $\frac{810}{135} = 6$ dishes per minute.
Combined rate: $9 + 6 = 15$ dishes per minute.

Step2: Calculate time together

Time = Total dishes / Combined rate = $\frac{810}{15} = 54$ minutes.

Answer:

54