A water tank is 2/5 th full. Inlet A can fill the tank in 12 minutes while an outlet pipe B can empty it in 6minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?
The average revenues of 7 consecutive years of a company is Rs 75 lakhs. If the average of first 4 years is Rs 70 lakhs and that of last 4 years is Rs 82 lakhs, what will be the revenue for the 4th year.