You can put this solution on YOUR website! Kelly earns $36 for 3 hours of work. At that rate, how long will she have to
work to earn $720?
$36 IS TO 3 hours AS $720 IS TO X hours.
"IS TO" means "OVER". "AS" means "EQUALS"
$36 OVER 3 hours EQUALS $720 OVER X hours.
CROSS MULTIPLY, that is,
"UPPER LEFT times LOWER RIGHT equals UPPER RIGHT times LOWER LEFT":
Divide both sides by $36
Answer: 60 hours
Edwin
