# Question 12012

$17 H o u r s$
To find how long it would take to earn $391. we first need to determine the rate at which Lenny is making money, usually in $/h as in $12.00/hour. For Lenny 9 hours earned$207: $/h = 207/9 $/h = 23 $\circ$Lenny is making good money for a HS student!
Then in order to find the hours to make $391, substitute for$ into the formula:
$/h = 23 $\frac{391}{h} = 23$$h = \frac{391}{23}$$h = 17$Check by estimation: 17 hours is one less than twice the original 9; and money earned $391 is $23 less than twice the original $207 xx 2 = 414#