Four children made the following statements.
Jeremiah : The average of Olivia's mass and my mass is 29 kg.
Jamie : I am the heaviest.
Olivia : Zoe is 2 kg lighter than Jamie.
Zoe : Our masses are in consecutive order.

What is the total mass of Jeremiah, Jamie and Olivia ?
Order of the mass of 4 children:
_____ , Zoe, _____ , Jamie (Heaviest)

Total mass of Jeremiah and Olivia 
= 2 x 29
= 58 kg

For Jeremiah and Olivia,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Jeremiah and Olivia
= 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 Jeremiah, Jamie and Olivia
= 28 + 30 + 31
= 89

Answer(s): 89 kg