The correct option is A Rs. 300
Given, when B sells the table to A,
Profit % =20
Gain = Rs. 69
Profit % =GainC.P.×100=20
⇒69C.P.×100=20
⇒ C.P. = Rs. 345
This CP of B is the SP for A, as A sold the table to B first.
Given, when A sells the table to B,
Profit % =15
So, at SP = Rs. 345, we have
Profit % =S.P.−C.P.C.P.×100=15
⇒345−C.P.C.P.×100=15
⇒345−C.P.=0.15C.P.
⇒1.15C.P.=345
⇒ C.P. = Rs. 300
Thus, A bought the table first for Rs. 300.