Correct Answer - Option 1 : 5

**Given:**

The average weight of the group = 44 kg

**Formula used:**

\(Average\ =\ {The\ sum\ of\ the\ all\ items \over The\ total\ number\ of\ items}\)

**Calculation:**

Let us assume the total boys in the group be X

⇒ The sum of the weight of the all-boys = 44X

⇒ 42X = 44X - 50 + 40

⇒ 42X = 44X - 10

⇒ 44X - 42X = 10

⇒ 2X = 10

⇒ X = 5

**∴ The required result will be 5.**