One half of the employees of Al Karim Co. earn salaries above Rs. 18,000 monthly. One third of the remainder earn salaries between Rs. 15,000 and Rs. 18,000. What part of the staff below Rs. 15,000?
If a pipe can fill a tank in 2 hours and another pipe can fill the same tank in 40 minutes. How much time in minutes is needed to fill the tank if both the pipes are working together?