Bill needs to soak his clothes for 4 minutes to get rid of each grass stain and 7 additional minutes to get rid of each marinara stain. If his clothes have 3 grass stains and 1 marinara stain, how long does he need to soak them?
First find the total soaking time to get rid of the grass stains: 4 minutes/stain * 3 stains = 
<gadget id="calculator">4*3</gadget>
<output>12</output>
12 minutes.
Then add the soak time for the marinara to find the total soak time: 12 minutes + 7 minutes = 
<gadget id="calculator">12+7</gadget>
<output>19</output>
19 minutes.

<result>19</result>