Answer:
ln 15 must be greater (larger than) if log 15 is common.
Explanation:
log 15 [assumed to be a common logarithm]
‹–› 15 = 10 ^ log(15)
ln 15 [natural log which has a base of e] ‹–› 15 = e ^ ln(15).
10 > e
e ≈ 2.7218.
e is approximately 3 rounded to the nearest whole number.
Logically you would need to raise 3 to a greater power for 3ⁿ = 15. Than 10ⁿ = 15.
For example 3² < 10² → 3³ < 10³ → 3⁴ < 10⁴ → ... Thus 3ⁿ < 10ⁿ for n > 0.