CAT Exam Model Paper 8 with solutions for free online practice

Let’s assume that 1 man does 1 unit of work in 1 day.
So the total units of work will be 150.
Work done in the first three days = 30 units
Next three days = 36 units
Next three days = 42 units
Next three days = 48 units
So, 156 units of work can be done in 12 days. But we have to do only 150 units. So on the last day, only 10 units of work is done.
Hence, the work gets completed on the 12th day.