On sports day, if 12 children were made to stand in each column, 98 columns could be formed. After a certain music being played the plan was that the children have to stand in concentric circles such that the innermost circle will have one student, the next circle will have two students, the third circle will have 3 students and so on. How many circles will be formed in this manner ?

Correct Answer: 48

No. of students will be 98 x 12 = 1176let us consider n circles then 1 + 2 + 3 + ....+ n = 1176n(n+1)/2 = 1176n = 48 circles.