Answer:
Step-by-step explanation:
Step one:
He charged $25 and spent $6 on gas on Monday.
then he made 25-6= $19 mowing his neighbor's lawn.
the next day is Tuesday(we are not told he spent any amount on gas on Tuesday).
So he mowed his Grandparents yard for $20.
total money saved for Monday and Tuesday is
19+20= $39
Hence he has $39 for mowing both yards