Four children made the following statements.
Lucas : Gavin is 2 kg heavier than Bryan.
Bryan : Our masses are in consecutive order.
Risa : The average of Lucas's mass and my mass is 47 kg.
Gavin : I am the heaviest.

What is the total mass of Risa, Gavin and Lucas ?
Order of the mass of 4 children:
_____ , Bryan, _____ , Gavin (Heaviest)

Total mass of Risa and Lucas
= 2 x 47
= 94 kg

For Risa and Lucas,
Mass of the lighter one = 1 u
Mass of the heavier one = 1 u + 2

Total mass of Risa and Lucas
= 1 u + 1 u + 2
= 2 u + 2

2 u + 2 = 94
2 u = 94 - 2
2 u = 92

1 u = 92 ÷ 2 = 46

The mass of the four children in consecutive order is 46, 47, 48 and 49.

Total mass of Risa, Gavin and Lucas
= 46 + 48 + 49
= 143

Answer(s): 143 kg