a number increased by 20 % gives 600. the number is Pick:	A) 250	B) 400	C) 450	D) 500	E) 520
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">600 / (6/5)</gadget>
<output>500</output>

<result>D</result>
a number increased by 20 % gives 600. the number is
divide(600, add(const_1, divide(20, const_100)))
"formula = total = 100 % , increse = ` ` + ' ' decrease = ` ` - ' ' a number means = 100 % that same number increased by 20 % = 120 % 120 % - - - - - - - > 600 ( 120 × 5 = 600 ) 100 % - - - - - - - > 500 ( 100 × 5 = 500 ) d )"