Answer:
Therefore, the first finished the book alone for the 6 days.
Therefore, the second finished the book alone, for the 12 days.
Step-by-step explanation:
We have that is the first one types twice as fast as the second one.
The first =2/3
The second =1/3
For first case we have the following proportion:
2/3 : 4=1 : x
x · 2/3 =4
x=6
Therefore, the first finished the book alone for the 6 days.
For second case we have the following proportion:
1/3 : 4=1 : x
x · 1/3 =4
x=12
Therefore, the second finished the book alone, for the 12 days.
