Which class has the maximum number of students from all schools together?

Total number of students of class V from all the school = Total number of students of ( School P + School Q + School R + School S + School T + School U )
Total number of students of class V from all the school = 152 +148 + 161 + 159 + 147 + 150 = 917
Total number of students of class VI from all the school = Total number of students of ( School P + School Q + School R + School S + School T + School U )
Total number of students of class VI from all the school = 160 + 166 + 152 + 142 + 144 + 160 + = 924
Total number of students of class VII from all the school = Total number of students of ( School P + School Q + School R + School S + School T + School U )
Total number of students of class VII from all the school = 145 +150 + 140 + 149 + 158 +162 = 904
Total number of students of class VIII from all the school = Total number of students of ( School P + School Q + School R + School S + School T + School U )
Total number of students of class VIII from all the school = 156 + 155 + 145 + 140 + 163 + 160 = 919
Total number of students of class IX from all the school = Total number of students of ( School P + School Q + School R + School S + School T + School U )
Total number of students of class IX from all the school = 147 + 157 + 143 + 142 + 154 + 161 =904
Total number of students of class X from all the school = Total number of students of ( School P + School Q + School R + School S + School T + School U )
Total number of students of class X from all the school = 144 + 143 + 165 + 168 + 150 + 140 = 910
Hence, the class VI has maximum number of students.