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

A. 0
B. 2
C. 4
D. 6

Answer: Option C

Explanation:

3x - y = 27 = 33    x - y = 3 ....(i)

3x + y = 243 = 35    x + y = 5 ....(ii)

On solving (i) and (ii), we get x = 4.