You'd need to identify your country of origin. In the US, if you were talking about truck classification based on Gross Vehicle Weight Rating, there are eight classes - 1 - 8, and no Class 61. Classification systems may vary elsewhere.
Class of '61 - 1993 TV is rated/received certificates of: Germany:12 Iceland:12
Class of '61 - 1993 TV was released on: USA: 12 April 1993
The Match Game - 1962 Show No- 61 1-61 is rated/received certificates of: USA:TV-G
Happy - 1960 Class of '61 2-10 was released on: USA: 17 March 1961
Chiquititas - 1995 5-61 is rated/received certificates of: Argentina:Atp
Kachorra - 2002 1-61 is rated/received certificates of: Argentina:Atp
Chiquititas - 1995 1-61 is rated/received certificates of: Argentina:Atp
Chiquititas - 1995 3-61 is rated/received certificates of: Argentina:Atp
Chiquititas - 1995 2-61 is rated/received certificates of: Argentina:Atp
Chiquititas - 1995 6-61 is rated/received certificates of: Argentina:Atp
If there are 55 children in the classroom then it is not possible for 61 of them ti be girls!
Montecristo - 2006 I 1-61 is rated/received certificates of: Argentina:16