Four children made the following statements.
Alexander : The average of Natalie's mass and my mass is 27 kg.
Anna : I am the heaviest.
Natalie : Dylan is 2 kg lighter than Anna.
Dylan : Our masses are in consecutive order.

What is the total mass of Alexander, Anna and Natalie ?
Order of the mass of 4 children:
_____ , Dylan, _____ , Anna (Heaviest)

Total mass of Alexander and Natalie 
= 2 x 27
= 54 kg

For Alexander and Natalie,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Alexander and Natalie
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 54 
2 u = 54 - 2
2 u = 52

1 u = 52 ÷ 2 = 26

The mass of the four children in consecutive order is 26, 27, 28 and 29.

Total mass of Alexander, Anna and Natalie
= 26 + 28 + 29
= 83

Answer(s): 83 kg