Four children made the following statements.
Harper : The average of Natalie's mass and my mass is 26 kg.
Wyatt : I am the heaviest.
Natalie : David is 2 kg lighter than Wyatt.
David : Our masses are in consecutive order.

What is the total mass of Harper, Wyatt and Natalie ?
Order of the mass of 4 children:
_____ , David, _____ , Wyatt (Heaviest)

Total mass of Harper and Natalie 
= 2 x 26
= 52 kg

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

Total mass of Harper and Natalie
= 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 Harper, Wyatt and Natalie
= 25 + 27 + 28
= 80

Answer(s): 80 kg