A water tank has holes. The 1st hole alone empties the tank in 9 min and 2nd hole alone empties the tank in 6 min. If water leaks out at a constant rate, how many min does it take if both the holes together empty the tank?
Ehsaan is twice as good a worker as Kamal and together they finish a piece of work in 29 days. In how many days will Kamal, working alone, finish the work?
In Feb 2016, which city topped the 'Swachh Survekshan - 2016' rankings of 73 cities in India with minimum open defecation and extensive adoption of solid waste management practices?