Answer:
The answer is 60 min.
Step-by-step explanation:
In order to determine the total time, we have to know about direct proportionality.
In math, two variables are said to be in a relation of direct proportionality if one variable increases, the other will increase too and the rate of both is a constant. The value of this constant is called the coefficient of proportionality.
In this case, if emma spends more time in the wall, she will build more wall.
So the constant is:

Now, applying this constant to a 100%:
T=total time

Finally, the total time is 60 min.