Discussion

The average of three numbers is 77. The first number is twice the second and the second number is twice the third. Then the first number is

Answer: D

The first number is 132.

Let the third number be \(t\). Then the second is \(2t\) and the first is \(4t\), and their total is three times the average:

\[ \begin{aligned} t + 2t + 4t &= 3 \times 77 = 231 \\ 7t &= 231, \ t = 33 \end{aligned} \]

So the numbers are 132, 66 and 33, and the first is 132. 33 and 66 are the third and second numbers, and 77 is the average.

Check: \((132 + 66 + 33)/3 = 231/3 = 77\), the given average.

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