Two-fifth of one-third of three-seventh of a number is 15. What is 40% of that number?
Correct answer: E. None of these
- A. 72
- B. 84
- C. 136
- D. 140
- E. None of these
Explanation
The given fraction is (2/5) x (1/3) x (3/7) = 2/35, so (2/35)n = 15 and n = 15 x 35/2 = 262.5. Hence 40% is (40/100) x 262.5 = 105, which is not among the choices, so option e is correct; option a, 72, comes from mishandling the compound fractions.
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