if 65 percent of a class answered the first question on a certain test correctly, 50 percent answered the second question on the test correctly, and 20 percent answered neither of the questions correctly, what percent answered both correctly?	Answers:
A) 25 %	B) 30 %	C) 35 %	D) 40 %	E) 45 %
<gadget id="calculator">65 + 50</gadget>
<output>115</output>

<gadget id="calculator">115 + 20</gadget>
<output>135</output>

<gadget id="calculator">135 - 100</gadget>
<output>35</output>

<result>C</result>
if 65 percent of a class answered the first question on a certain test correctly, 50 percent answered the second question on the test correctly, and 20 percent answered neither of the questions correctly, what percent answered both correctly?
subtract(add(add(65, 50), 20), const_100)
"65 % answered the first question correctly and 20 % answered neither correctly . then 15 % missed the first question but answered the second question correctly . then the percent who answered both correctly is 50 % - 15 % = 35 % . the answer is c ."