The difference between a number and its two fifth is 510. What is 10% of that number?  Select the correct option.
A) 12.75 B) 50 C) 85 D) 204 E) None
Solution   Let the number be x.   Then, x - 2 / 5 x = 510.   ‹=›3 / 5 x = 510   ‹=›x = [510 x 5 / 3] = 850.   Therefore 10% of 850 = 85.   Answer 85
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The difference between a number and its two fifth is 510. What is 10% of that number?