The average of six numbers is x and the average of three is y. If the average of the remaining three is z, then :
A
x=y+z
B
x=2y+2z
C
2x=y+z
D
none of these
Correct Answer: 2x=y+z
Hints: Average of 6 numbers = x sum of 6 numbers = 6x Average of the 3 numbers = y sum of the 3 numbers = 3y Average of the remaining 3 numbers = z sum of the remaining 3 numbers = 3z Now, we know that 6x = 3y + 3z 2x = y + z