Take Pleasant Goat as the research object first, and you can easily find it.

Pleasant goat's rest day is a multiple of 5, namely 5, 10, 15, 1000.

Then the boiling sheep only needs a multiple of 5 days' rest.

Taking boiling sheep as the research object, his rest days are: 8, 9, 10, 18, 19, 20. ...

In this way, you can easily find that all three numbers are not multiples of 5, which means that boiling sheep will have a coincidence of 1 day (that is, the tenth day) every 10 day.

Then with 10 as the period, * * has1000/10 =100 cycles.

If one day of each cycle coincides, then 100 cycles * * * have 100 days.

Ps+ tucao: the current math problem is too. Better change your name. Insulting the IQ of the flowers of the motherland.