The mean of two numbers x and y is 4. Find the mean of four numbers x, 2x, y and 2y
A
2
B
4
C
6
D
8
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Since the mean of the two numbers x and y is:
\(\frac{x+y}{2}\) = 4
x+y =2 * 4
x+y = 8
then we get:
\(\frac{x+2x+y+2y}{4}\)
=(\(\frac{3x+3y}{4}\))
= 3(\(\frac{x+y}{4}\)) → 3(\(\frac{8}{4}\))
= 3 * 2
= 6
Source: WAEC / JAMB / NECO Classroom Archive (Record #65394)