Answer:
3) 2.7
Step-by-step explanation:
The distance between two points
and
can be determined by:

Since the points are X(1, 2) and Y(6, 7). The distance between the two points is

the x value for the point located 1/3 the distance from X to Y,

The x value = 
If each garden takes 20 minutes to clean, it will take him (20 x 4) to clean the gardens.
20 x 4 = 100
80 minutes
or 1 hour and 10 minutes.
I can’t really explain but this is my working step by step, hope u can understand and see if it helps you :)