Four children made the following statements.
Emma : Nathan is 2 kg heavier than Riordan.
Riordan : Our masses are in consecutive order.
Mason : The average of Emma's mass and my mass is 31 kg.
Nathan : I am the heaviest.

What is the total mass of Mason, Nathan and Emma ?
Order of the mass of 4 children:
_____ , Riordan, _____ , Nathan (Heaviest)

Total mass of Mason and Emma
= 2 x 31
= 62 kg

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

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

2 u + 2 = 62
2 u = 62 - 2
2 u = 60

1 u = 60 ÷ 2 = 30

The mass of the four children in consecutive order is 30, 31, 32 and 33.

Total mass of Mason, Nathan and Emma
= 30 + 32 + 33
= 95

Answer(s): 95 kg