Question

Question 12

The average mass of Jeremy, Mark and Zack is 28 kg. If Jeremy and Zack's average mass is
29kg. How heavy is Mark?​

Answer 1

Mark's mass is 26 kg.

Explanation:

Average mass of Jeremy, Mark and Zack = 28kg

Average mass of Jeremy and Zack = 29 kg

Let,

Jeremy's mass = x

Mark's mass = y

Zack's mass = z

Average of three of them =
`(Jeremy's mass + Mark's + Zack's)/(3)`

28 =
`(x+y+z)/(3)\\`

`28*3 = x+y+z\\84 = x+y+z`

x+y+z = 84 Eqn 1

`29 =(x+z)/(2)\\58=x+z\\`

x+z = 58 Eqn 2

Now putting value of x+z from Eqn 2 in Eqn 1

x + z + y = 84

58 + y = 84

y = 84 - 58

y = 26

Thereofore,

Mark's mass is 26 kg.