What is the difference between total number of students with IT specialisation from all the institutes together and the total number of students with Mechanical specialisation from all the institutes together ?

what is the ratio between total number of students in institutes R and V respectively ?

If the number of students with Mechanical Specialisation in each institute increased by 20% and the number of students with Electronic specialisation in each institutes decreased by 15% from 2012 to 2013, total number of students with Mechanical from all the institutes in 2013 is approximately, what percent of the total number of students with Electronics specialisation from all the institutes in 2013 ?

 I. x²-72=x

II. y²=64

 I. x²= 961

II. y=√961

 I. x²+7x+12=0

II. Y²+6y+8=0