Question

1. If 2x + y = 5; 3y + z = 15 and 3z + 2x = 16, then

what is the average (arithmetic mean) of x, y and
z??
A. 2
B, 3
C. 5
D. 12
E. 13

Answer 1

B.) 3

Explanation:

2x+y=5

3y+z=15

3z+2x=16

__________

4x+4y+4z=36 ( Added all the Equations)

x+y+z=9 (Divided by four)

Since we're trying to find the average, we have to add x, y, and z, and then divide by three (x is one, y is the second, and z is the third) because the average is the sum of all the numbers divided by the amount of numbers.

x+y+z=9

Average(x+y+z)=3