Work Problems - Easy 2

Kiosk A completed half of the job before Kiosk B joined Kiosk A. So half of $12$ hours is $6$ hours.

However, we can use the same equation on the previous problem to get the combined work of both kiosks.

$\frac {xy}{x+y}$ = $\text{number of total hours if worked together}$

$\frac {(12)(18)}{12+18} = \frac {216}{30} = 7.2$

Since half of the work is already done, divide $7.2$ by $2$ . You will get $3.6$ .

Now they will complete their job in $6 + 3.6 = \boxed{9.6}$ hours.