Question

38. 3^x=11, 11^y=81. xy=?
A) 3
C) 5
B) 4
D) None of these

Answer 1

I think, option D is the correct one..

Answer: None of these.

Answer 2

Answer:

3^x=11, 11^y=81

Take log both side

x*log3 = log11

x = log11 / log3

y*log11 = log81

y = log81/log11

Multiply xy -

xy = log81/log3

xy = 4*log3/log3

So,

xy = 4