Question

Question 12

Answer 1

Answer:

Mark's mass is 26 kg.

Step-by-step 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 = $\frac{Jeremy's mass + Mark's + Zack's}{3}$

28 = $\frac{x+y+z}{3}$

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

x+y+z = 84     Eqn 1

$29 =\frac{x+z}{2}\\58=x+z$

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.