Comprehension Passage

Directions: The given table shows the number of students studying in three different class such as X , XI and XII from four different schools

Name of the school	Number of students studying in class X	Number of students studying in class XI	Number of students studying in class XII
A	250	200	180
B	150	160	220
C	140	120	180
D	160	300	100

Find the difference between the number of students studying in class XI from school C and the number of students studying in class XII from school D.