Four children made the following statements.
Joseph : The average of Gavin's mass and my mass is 26 kg.
Jacob : I am the heaviest.
Gavin : Ella is 2 kg lighter than Jacob.
Ella : Our masses are in consecutive order.

What is the total mass of Joseph, Jacob and Gavin ?
Order of the mass of 4 children:
_____ , Ella, _____ , Jacob (Heaviest)

Total mass of Joseph and Gavin 
= 2 x 26
= 52 kg

For Joseph and Gavin,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Joseph and Gavin
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 52 
2 u = 52 - 2
2 u = 50

1 u = 50 ÷ 2 = 25

The mass of the four children in consecutive order is 25, 26, 27 and 28.

Total mass of Joseph, Jacob and Gavin
= 25 + 27 + 28
= 80

Answer(s): 80 kg