In a town where 60% of the citizens own a pet, half own a dog and 30 own a cat. How many citizens are in the town?
Half the pet-owners have a cat because 1 - 1/2 = 1/2.
There are 60 pet owners because 30 / (1/2) = 
<gadget id="calculator">30/(1/2)</gadget>
<output>60</output>
60.
The town has 100 citizens because 60 / .6 = 
<gadget id="calculator">60/.6</gadget>
<output>100</output>
100.

<result>100</result>