Four children made the following statements.
Mason : The average of Benjamin's mass and my mass is 36 kg.
Dylan : I am the heaviest.
Benjamin : David is 2 kg lighter than Dylan.
David : Our masses are in consecutive order.

What is the total mass of Mason, Dylan and Benjamin ?
Order of the mass of 4 children:
_____ , David, _____ , Dylan (Heaviest)

Total mass of Mason and Benjamin 
= 2 x 36
= 72 kg

For Mason and Benjamin,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Mason and Benjamin
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 72 
2 u = 72 - 2
2 u = 70

1 u = 70 ÷ 2 = 35

The mass of the four children in consecutive order is 35, 36, 37 and 38.

Total mass of Mason, Dylan and Benjamin
= 35 + 37 + 38
= 110

Answer(s): 110 kg