If the difference between number of students opted for traditional and professional courses from Amber college in 2021 is x and sum of the number of students opted for professional course from Dhara college in 2019 and 2020 together is y then find the sum of the values of x and y.

Question

Years	Number of students in Amber and Dhara colleges opted for both the courses	Number of students in Amber colleges opted for traditional courses	Number of students in Amber colleges opted for professional courses	Number of students in Dhara colleges opted for traditional courses	Number of students in Dhara colleges opted for professional courses	Number of students in Dhara college opted for both the courses
2019	150	—-	2P	—-	4P	70
2020	200	—-	2P	—-	—-	80
2021	321	—-	3P	—-	—-	99