The difference between a number and its two-fifth is 510. What is 20% of that number?  Select the correct option:	A) 177	B) 170	C) 172	D) 174	E) 171
Let the number be x. Then,   x - 2/5 x = 510   x = (510 * 5)/3= 
<gadget id="calculator">(510 * 5)/3</gadget>
<output>850</output>
850   20% of 850= 170.   Answer:170
<result>B</result>
The difference between a number and its two-fifth is 510. What is 20% of that number?