The average of six numbers is x and the average of three of these is y. If the average of the remaining three is z, then	Choose the correct answer.
A) None of these B) x = y + z C) 2x = y + z D) x = 2y + 2z E) x = y + 2z
Explanation:   Average of 6 numbers = x   =&gt; Sum of 6 numbers = 6x   Average of the 3 numbers = y   =&gt; Sum of these 3 numbers = 3y   Average of the remaining 3 numbers = z   =&gt; Sum of the remaining 3 numbers = 3z   Now we know that 6x = 3y + 3z   =&gt; 2x = y + z   Answer: Option 2x = y + z
<result>C</result>
The average of six numbers is x and the average of three of these is y. If the average of the remaining three is z, then