The difference between a number and its two-fifth is 510. What is 30% of that number?
Choose the correct choice from the following answers:
A) 158  B) 200  C) 255  D) 400  E) 280
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   10% of 850= 255.   Answer:255
<result>C</result>
The difference between a number and its two-fifth is 510. What is 30% of that number?