En la terminal del norte de la ciudad de mexico tienen varias corridas hacia el norte del pais la primera sale cada 10 minutos la segunda cada 12 la tercera cada 15 y la cuarta cada 30. si hoy es lunes y salieron juntas a las 7:00 am ¿a que hora saldran juntas nuevamente? ¿cunatas corridas se realizaran en total si contar las iniciales?

3+x

step-by-step explanation:

-1   1/6.   you dont subtract the denominators

step-by-step explanation:

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."