He first keeps the cockroach on one edge of a table, lets it go while asking it to jump. It jumps. Now he pulls off one of its legs and keeps it over the table. Again he asks it to jump. Again cockroach jumps. Getting boosted by this development, now he cuts another leg and asks the cockroach to jump. The cockroach jumps again. Getting excited, now he cuts the third leg and again asks it to jump. cockroach jumps. Now he could not control the suspense and cuts the fourth leg and ask the cockroach to jump. Same happens until all legs are gone and finally, when all last leg is gone, cockroach does not jump.
Immediately, the sardar writes in his thesis conclusion “If you cut all the legs of a cockroach, it will become deaf.”