Four children made the following statements.
Julie : The average of Tommy's mass and my mass is 43 kg.
Liam : I am the heaviest.
Tommy : Ella is 2 kg lighter than Liam.
Ella : Our masses are in consecutive order.

What is the total mass of Julie, Liam and Tommy ?
Order of the mass of 4 children:
_____ , Ella, _____ , Liam (Heaviest)

Total mass of Julie and Tommy 
= 2 x 43
= 86 kg

For Julie and Tommy,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Julie and Tommy
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 86 
2 u = 86 - 2
2 u = 84

1 u = 84 ÷ 2 = 42

The mass of the four children in consecutive order is 42, 43, 44 and 45.

Total mass of Julie, Liam and Tommy
= 42 + 44 + 45
= 131

Answer(s): 131 kg