Question #be954

1 Answer
Feb 12, 2018

See below...

Explanation:

First lets make sure that the fractions have the same denominator, in this case #20#.

#therefore#

#2/5 * 4/4 = 8/20#
#1/4 * 5/5 = 5/20#

Together they have mowed #8/20 + 5/20 = 13/20#

Treat the whole lawn as #1# which is the same as #20/20#

#therefore 20/20 - 13/20 = 7/20#

Therefore #7/20# of the lawn still needs mowing.