Hello snigdhaI assume that the bit I've marked in red should be AD//PQ//BC.

Do you know how to use vectors to solve problems like this? If you do, it's quite easy. Let and . Then

, for some number

And , since Q is the mid-point of DC.

, for some number

But

Compare coefficients:

So AS = AC.

Also, R is the mid-point of AC (since triangles APR and CQR are congruent), and so RC = AC RC : SC = 3 : 2

area triangle CQR : area triangle SCQ = 3:2, since they share the same height.

Do you want to see if you can finish it now?

Grandad