Question

Find the integral part of log₂20000.
1. 6
2. 12
3. 14
4. 15

Answer 1

Correct Answer - Option 3 : 14

Calculation:

log₂20000 = log₂(625) (32)

= log ₂625 + log₂32
= log₂625 + 5
2⁹ = 512 and 2¹⁰ = 1024
∴ log₂625 lies between 9 and 10.
∴ The log₂20000 lies between 14 and 15 and its integral part is 14.

If instead of base 2 we have 10 then the number of the digit will be equal to the integral part of log₁₀b + 1.