Question

Three pipes a, b and c are attached to a cistern. a can fill it in 10 minutes and b in 15 minutes, c is a leak pipe. after opening both the pipes a and b, a man leaves the cistern and returns when the cistern should have been full. finding however, that the waste pipe had been left open, he closes it and the cistern now filled in 2 minutes. in how much time pipe c will take to empty the full cistern

Answer 1

its too long ans hio