Study the following table and answer the question:
Number of students Appeared (A) and Passed (P) in an annual examination from four schools Q, R, S & T in five years (2014 to 2018)

The ratio of the total number of students appeared from school Q in 2017 and from school S in 2018 to the total number of students passed from school R in 2018 and school T in 2014, is:

25 : 21

Appeared (Students of Q in 2017 + students of S in 2018)  : Passed (Students of R in 2018 + students of T in 2014) 

    ( 350 + 400 )      :       ( 405 + 225 )

           750              :            630

            25               :            21