The given information is:
Archie earns $9/hour for babysitting, $6/hour for pet walking and $5/hour for house sitting.
4. If he babysits for 4 hours, walks pets for 2 hours and house sits for 6 hours he will earn:
He makes this week $78
5. If he babysits for 3 hours he will earn:
$27
And if he walks pets for 4 hours, he will earn:
$24
Thus, he makes more money babysitting for 3 hours than pet walking for 4 hours.
And the difference is $27-$24=$3.
He will earn $3 more.