The fourth proportional to 12, 15 and 20 is?  Answers:
A) 21  B) 66  C) 25  D) 99  E) 26
(15*20)/12= 
<gadget id="calculator">(15*20)/12</gadget>
<output>25</output>
25   Answer: 25
<result>C</result>
The fourth proportional to 12, 15 and 20 is?