Four children made the following statements.
Josiah : William is 2 kg heavier than Abigail.
Abigail : Our masses are in consecutive order.
Olivia : The average of Josiah's mass and my mass is 41 kg.
William : I am the heaviest.

What is the total mass of Olivia, William and Josiah ?
Order of the mass of 4 children:
_____ , Abigail, _____ , William (Heaviest)

Total mass of Olivia and Josiah
= 2 x 41
= 82 kg

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

Total mass of Olivia and Josiah
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 82
2 u = 82 - 2
2 u = 80

1 u = 80 ÷ 2 = 40

The mass of the four children in consecutive order is 40, 41, 42 and 43.

Total mass of Olivia, William and Josiah
= 40 + 42 + 43
= 125

Answer(s): 125 kg