Four children made the following statements.
Evan : The average of Julian's mass and my mass is 29 kg.
Rebecca : I am the heaviest.
Julian : Isaiah is 2 kg lighter than Rebecca.
Isaiah : Our masses are in consecutive order.

What is the total mass of Evan, Rebecca and Julian ?
Order of the mass of 4 children:
_____ , Isaiah, _____ , Rebecca (Heaviest)

Total mass of Evan and Julian 
= 2 x 29
= 58 kg

For Evan and Julian,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Evan and Julian
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 58 
2 u = 58 - 2
2 u = 56

1 u = 56 ÷ 2 = 28

The mass of the four children in consecutive order is 28, 29, 30 and 31.

Total mass of Evan, Rebecca and Julian
= 28 + 30 + 31
= 89

Answer(s): 89 kg