Answer:
20 lawns
Step-by-step explanation:
Considering the attached table then we say that if 4 lawns require 7 hours, how many lawns for 35 hours.
By cross multiplication
35*4/7=20 lawns
Therefore, given 35 hours, they will plough 20 lawns.
Alternatively, by finding the rate per lawn, one lawn takes 7/4 hours then if given 35 hours we divide the given hours by rate per hour. The number of lawns will still be 20 lawns