Question: how many ruku in 1 para?
Answer: There are 540 rukus in Quran. This subdivision is not part of original revelation but adopted later-on to facilitate completion of Quran on the 27th night of Ramadhan (i.e. on Laylatul Qadr) if one ruku is recited in each rakat of taraweeh prayers (20 x 27 = 540).