A sum of ₹ y is divided among four persons P, Q, R and S such that four times of P’s share is equal to five times of Q’s share, seven times of Q’s share is equal to eight times of R’s share and eleven times of R’s share is equal to seven times of S’s share. If the difference between the shares of S and Q is ₹ 3720, then find the value of ‘y’?