Four children made the following statements.
Sofia : The average of William's mass and my mass is 48 kg.
Charlotte : I am the heaviest.
William : Ava is 2 kg lighter than Charlotte.
Ava : Our masses are in consecutive order.

What is the total mass of Sofia, Charlotte and William ?
Order of the mass of 4 children:
_____ , Ava, _____ , Charlotte (Heaviest)

Total mass of Sofia and William 
= 2 x 48
= 96 kg

For Sofia and William,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Sofia and William
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 96 
2 u = 96 - 2
2 u = 94

1 u = 94 ÷ 2 = 47

The mass of the four children in consecutive order is 47, 48, 49 and 50.

Total mass of Sofia, Charlotte and William
= 47 + 49 + 50
= 146

Answer(s): 146 kg