Well this is how I worked it out; do let me know if I have done it right.

Suppose, initially, the subscription fee was "x". After a 20 per cent reduction, the new subscription fee is 4x/5.

Suppose initially the number of members was "y", then the collection would have been xy.

There has been a 60 per cent increase in the collection amount. The new collection amount is therefore [xy + (60xy)/100] = (160xy)/100.

Number of members = Total collection / subscription fee. Therefore the number of members now = (160xy/100) / (4x/5) = 2y.

Initially, the number of members was "y" and now it is "2y". Therefore, the percentage increase = 100.

Some useful links for
your career:

  • Union Public Service Commission -
  • IIT-Kharagpur -
  • Indian Statistical Institute -
  • Indian Institute of Technology Madras -
  • Indian Institute of Management, Ahmedabad -
  • Indian Institute of Mass Commission -
  • IIT Bombay -
  • Indian School of Mines, Dhanbad -
  • Birla Institute of Technology, Ranchi -
  • Central Institute of Fisheries Nautical and Engineering Training -
  • Indian Institute of Information Technology, Allahabad (Deemed University) -
  • Central Marine Fisheries Research Institute, Kochi -
  • Tata Institute of Social Sciences, Mumbai -