To check the principle of multiple proportions, a series of pure binary compounds (P$$_m$$Q$$_n$$) were analyzed and their composition is tabulated below. The correct option(s) is(are)

Compound	Weight % of P	Weight % of Q
1	50	50
2	44.4	55.6
3	40	60

If empirical formula of compound 3 is P$$_3$$Q$$_4$$, then the empirical formula of compound 2 is P$$_3$$Q$$_5$$.

If empirical formula of compound 3 is P$$_3$$Q$$_2$$ and atomic weight of element P is 20, then the atomic weight of Q is 45.

If empirical formula of compound 2 is PQ, then the empirical formula of the compound 1 is P$$_5$$Q$$_4$$.

If atomic weight of P and Q are 70 and 35, respectively, then the empirical formula of compound 1 is P$$_2$$Q.