Q1: If 3^(x - y) = 27 and 3^(x + y) = 243, then x is equal to:

ANS:C - 4

3^x - y = 27 = 3³        x - y = 3 ....(i) 3^x + y = 243 = 3⁵        x + y = 5 ....(ii) On solving (i) and (ii), we get x = 4.