If Ann cleans in 12 hours then she cleans

of the apartment per hour. Similarly Liz cleans

of the appartment per hour. So together then can clean

of the apartment for hour. Therefor it will take them

hours to clean.
The general formula

can be used as a check if needed.
A stem and leaf plot is a table where each of the data is divided into two parts. The stem, that is the first digit and the leaf is the last digits. Let's say that we have the following set of data.

If we want to make a stem and leaf plot of that data, we first write a column where we place the first digit of each number without repetition, like this:

These are the stems. Now the leaves are the last digit of each number put in order next to the corresponding first digit, like this:
Answer:
-692784311700
Step-by-step explanation: