Jerry is twice as old as he was 5 years ago. How old will Jerry be in 3 years?
We know that Jerry's Age/2 = Jerry's Age - 5.
Therefore Jerry's Age = 2 Jerry's age - 10.
Therefore -Jerry's Age = - 10.
Therefore Jerry's Age = 
<gadget id="calculator">10</gadget>
<output>10</output>
10.
In three years Jerry will be 13 because 10 + 3 = 
<gadget id="calculator">10+3</gadget>
<output>13</output>
13.

<result>13</result>