Height of the plant before placing by a window = 8 inches
The number of days required by the plant to increase 3 inches = 1 day
Now the length of the actual plant has to be deducted from 26 inches.
Length by which the plant
actually grows after putting it by the window = 26 - 8
= 18 inches
So
The number of days required by
the plant to increase by 18 inches = 18/3 days
= 6 days
So the plant will require 6 days to reach a length of 26 inches.