There was a big sale on cat food at the pet store. 20 people bought cat food that day. The first 8 customers bought 3 cases each. The next four customers bought 2 cases each. The last 8 customers of the day only bought 1 case each. How many cases of cat food were sold?
The first 8 customers bought 8*3=
<gadget id="calculator">8*3</gadget>
<output>24</output>
24 cases.
The next 4 customers bought 4*2=
<gadget id="calculator">4*2</gadget>
<output>8</output>
8 cases.
The last 8 customers bought 8*1=
<gadget id="calculator">8*1</gadget>
<output>8</output>
8.
In total 24+8+8=
<gadget id="calculator">24+8+8</gadget>
<output>40</output>
40 cases were sold.

<result>40</result>