Question 1201474
<pre>
 The sum of the digits of a three-digit number is 6. The hundreds digit is twice the units digit, 
     and the tens digit equals the sum of the other two. Find the number.

Let units digit be U
Then hundreds digit = 2U
Since the tens digit is equal to the sum of the other 2, the tens digit is U + 2U = 3U
Since ALL digits sum to 6, we get: 2U + 3U + U = 6
                                            6U = 6
                            Units digit, or {{{highlight_green(matrix(1,5, U, "=", 6/6, "=", 1))}}}
                            Hundreds digit: 2U = 2(1) = 2
                                Tens digit: 3U = 3(1) = 3
                                              <font color = red><font size = 4><b>Number: 231</font></font></b></pre>