Correct Answer - Option 2 : 16

**Given:**

Initial number of men = 16

Initial time is to be needed = 12

**Formula used:**

M1D1/W1 = M2D2/W2

Where,

M1 = Men , D1 = Days1

M2 = Men2 , D2 = Days2

W1 = Work , W2 = Work2

**Calculation:**

Total work = 16 × 12 = 192

Work completed = 16 × 4 = 64

Remaining work = 192 – 64 = 128

This work is to be completed in 4 days

So number of worker required = 128/4 = 32

No of more men required is 32 – 16 = 16

**∴ So 16 more men is required.**