A child learns new words very quickly, but their vocabulary grows slower as they grow up. There is no upper-limit to the size of
a person's vocabulary, so a logarithmic growth model is reasonable. The number of words can be related to the child's age (in months) according to the following formula: W(m)=10,000 ⋅ log(m) − 13,000 where m is the number of months in a person's age.
How many vocabulary words would a person have after 20 years (240 months) ?
