Five persons fire bullets at a target at an interval of 6,7,8,9 and 12 seconds respectively. The number of times they would fire the bullets together at the target in an hour is
6
7
8
9
Next Question
A group of 630 children is seated in rows for a group photo session. Each row contains three less children than the row in front of it. Which one of the following number of rows is not possible?