Final answer:
To spray 1 entire lawn, it would take approximately 12 4/5 liters of weed killer.
Step-by-step explanation:
To find out how many liters of weed killer would it take to spray 1 entire lawn, we need to set up a proportion using the given information. We know that 3 1/5 liters can spray 1/4 of a lawn. Let x represent the number of liters needed to spray 1 entire lawn.
Therefore, we have the proportion: 3 1/5 liters is to 1/4 of a lawn as x liters is to 1 entire lawn.
To solve the proportion, we can cross multiply: (3 1/5) * (1) = (1/4) * (x).
Simplifying the equation, we get: 16/5 = x/4.
So, x = (16/5) * 4 = 64/5 = 12 4/5.
Therefore, it would take approximately 12 4/5 liters of weed killer to spray 1 entire lawn.