A project company hired 10000 casual employees to undertake a major housing project for 2 weeks. On average (daily) these workers take 10 hours to complete a given task with a s.d deviation of 2.5...

A project company hired 10000 casual employees to undertake a major housing project for 2 weeks. On average (daily) these workers take 10 hours to complete a given task with a s.d deviation of 2.5 hours. If completion time is normally distributed, determine the no. of workers who completed the task in:-

i.       Less than 7 hours

1. Less than 12.5 hours


2. More than 13.5 hours


3. Between 6.75 hours and 14.75 hours


4. Between 5.85 hours and 8.85 hours


5. Between 12.75 hours and 15.95 hours


6. If the firm decides to lay off all the workers who cannot complete the task within 16.5 hours, how many workers will the firm lay-off?