WordGPT

Which is bigger, 5305^{30} or 30530^{5}?

5305^{30} is bigger: 5305^{30} = 9.31322 × 102010^{20} and 30530^{5} = 24300000.

The curve ln x / x, which decides every comparison of a^b with b^a510152025300.10.150.20.250.30.350.4x = 5x = 30peak at eln x / x
The curve ln x / x, which decides every comparison of a^b with b^a. 5^30 against 30^5 is the same question as which of the two marked points is higher; the curve peaks at x = e.

How to work it out

  1. 1

    Compute both exactly: 5305^{30} = 931322574615478515625 and 30530^{5} = 24300000.

  2. 2

    So 5305^{30} is bigger.

  3. 3

    The reason: taking logs, aba^{b} against bab^{a} is the same as ln⁡aa\frac{\ln a}{a} against ln⁡bb\frac{\ln b}{b}. The function ln⁡xx\frac{\ln x}{x} rises until x=e≈2.718x = e \approx 2.718 and falls afterwards. Both 5 and 30 are past e, where the function is decreasing, so the larger exponent loses and 5305^{30} > 30530^{5}.

    ln⁡55 > ln⁡3030\frac{\ln 5}{5}\ >\ \frac{\ln 30}{30}
LaTeX source of the formulas on this page
\[ 5^{30} = 9.31322\times 10^{20}\ >\ 30^{5} = 24300000 \]
\[ \frac{\ln 5}{5}\ >\ \frac{\ln 30}{30} \]

Questions

Which is bigger, 5305^{30} or 30530^{5}?

5305^{30} is bigger: 5305^{30} = 9.31322 × 102010^{20} and 30530^{5} = 24300000.

Similar comparisons

    Which is bigger, 5^30 or 30^5? 5^30 | WordGPT