0 0 votes Some persons are standing at distinct points on a circle, all facing towards the center. Each possible pair of persons who are not adjacent sing a three-minute song, one pair after another. If the total time taken by all the pairs to finish singing is $1$ hour, find the number of persons standing on the circle $5$ $7$ $9$ $8$ Quantitative Aptitude cat2013 quantitative-aptitude speed-distance-time + – admin 5.3k points 1.3k views answer comment Share Follow Print 0 reply Please log in or register to add a comment.