math help plz?

Question

the average of x and y is 5
and the average of x,y,z is 8 whati is the value of z

someone help me and is there an equation or something

Answer 1

z is 14

If the AVERAGE of x and y is 5, just make both of them 5. Or better yet, their sum is 10.

If the average of x, y, and z is 8, that means the sum of x,y, & z is 24.

24 - 10 = 14.

Answer 2

well the average is all the numbers added up, then divided byt the number of numbers, so like
(x+y) / 2 = 5

(x+y+z) / 3 = 8

do process of elimination

or just think about it...its not that hard, z = 14

because x+y=10 (because you divide the answer by 2 and get 5)

so x+y+z = 10 + z, and the answer needs to be 24 (because 24 / 3 is the only way to get the answer 8)

so 10 + [what number] = 24
10+14 = 24

therefore z=24

Answer 3

if x + y 's average is 5, the 5 must equal (x + y)/2

(x + y + z)/3 = 8

x + y = 10

x + y + z = 24

but we know that x + y = 10, so we can write

10 + z = 24,

therefore z = 14

Answer 4

z=14

Answer 5

well just use common sense. let (X+Y)/2 =5 so X+Y=10 right? Then (10+Z)/3 =8. What's Z now?

Answer 6

(x+y)/2=5............x+y=10

(10+z)/3=8..........10+z=24

z=14