@ pappu
this is a direct formula based ques . u can solve it by direct formula .
i am giving the formula in which u can correctly approach the question .
u are given with molar conductivity = 138.9 siemen cm ^2 ( delta m )
concentration terms = 1.5 M .
so, the ques is asking to find out specific conductance ( kappa )
now , acc to the formula
molar conductivity = kappa / conc . terms .
so, kappa = molar conductivity * conc terms
just multiply the two and get the answer .
HOPE U CAN DO THAT NOW , IF NOT THEN LET ME KNW
ALL THE BEST ..