If one-third of one-fourth of a number is 15, then three-tenth of that number is:
Answer: D
Let the number be x.
One-third of one-fourth of the number is \((\frac{1}{3}) \times (\frac{1}{4}) \times x = 15\).
\(\frac{x}{12} = 15\), so x = 180.
Now, we need to find three-tenth of the number:
\((\frac{3}{10}) \times 180 = 3 \times 18 = 54\).