a school is divided into 4 houses,P,Q,R and S.On sports day,the students line up so that a student from P is first in line,then a student from Q then a student from R then a student from S,then a student from P and so on with same order repeating.From what house will the 66th student come?

Answer 1

every 4 days the cycle is complete.
After 64 days, we're back to the start.

so, the 66th student will be from Q.