The boat is traveling at a rate of 1 meter per second. How long does it take the barnacle to get back to its starting point?

so what is the problem what are they asking you to solve

step-by-step explanation:

so what is the problem what are they asking you to solve

there is only one way to arrange all the eight relative to each other because they are not distinct. we have

now there are nine places to place an (and not more than one in one place).   because we have four symbols, we need to choose four of these nine places to insert an . order does not matter because the are not distinct.

thus there are 1 · c(9,4) ways, or, if we calculate it,

thus there are 126 ways to form such "words."

38 was the other number of your question.