Four children made the following statements.
Riordan : Ellie is 2 kg heavier than Harris.
Harris : Our masses are in consecutive order.
Julie : The average of Riordan's mass and my mass is 28 kg.
Ellie : I am the heaviest.

What is the total mass of Julie, Ellie and Riordan ?
Order of the mass of 4 children:
_____ , Harris, _____ , Ellie (Heaviest)

Total mass of Julie and Riordan
= 2 x 28
= 56 kg

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

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

2 u + 2 = 56
2 u = 56 - 2
2 u = 54

1 u = 54 ÷ 2 = 27

The mass of the four children in consecutive order is 27, 28, 29 and 30.

Total mass of Julie, Ellie and Riordan
= 27 + 29 + 30
= 86

Answer(s): 86 kg