Question

Lea and Marie are washing all the windows in their house. It would take Lea 80 minutes to wash the windows by herself, and it would take Marie 60 minutes to wash them by herself. Lea creates a table so she can find out how long it will take to wash the windows if they work together. What is the missing value in the table that represents the rate for Marie?

A. 1/60
B. 1/100
C. 1/120
D. 1/40

Answer 1

Marie's rate for washing windows is the reciprocal of the time it takes her to do it alone, which is 1/60 windows per minute. This is the missing value in the table.

Step-by-step explanation:

You've asked about Lea and Marie washing windows together and what the missing value in the table representing Marie's rate is. We know Lea can wash the windows by herself in 80 minutes and Marie in 60 minutes. To find each person's rate (windows per minute), we take the reciprocal of the time it takes them to wash all the windows. Lea's rate is 1/80 windows per minute. Now, let's calculate Marie's rate.

Marie's rate can be found by taking the reciprocal of the time it takes for her to wash all the windows by herself, which would be 1/60. Therefore, the missing value in the table that represents the rate for Marie is 1/60 windows per minute.