A sum of Rs. 1300 is divided among P, Q, R and S such that `(P^(prime)s s h a r e)/(Q^(prime)s s h a r e)=(Q^(prime)s s h a r e)/(R^(prime)s s h a r e)=(R^(prime)s s h a r e)/(S^(prime)s s h a r e)=2/3dot` How much is Ps share? `R s .140` b. `R s .160` c. `R s .240` d. `R s .320`