If z satisfies the equation 8^z = 256, then z is equal to __________. A. log_16 8 B. log_2 8 C. 8/3 D. log_4 8

GATE 2023 · General Aptitude · Logarithms · medium

Answer: z = 8/3

  1. Express both sides as powers of 2: 8^z = 256 => (2^3)^z = 2^8
  2. Apply power-of-a-power rule: (2^3)^z = 2^(3z) so the equation becomes 2^(3z) = 2^8
  3. Equate exponents and solve: 3z = 8 => z = 8/3