In a particular year there were exactly four Mondays in January as well as exactly four Fridays that month. What day of the week was January 1?
A 31 day month has 3 days that occur exactly five times. They must be consecutive - thus Tuesday, Wednesday, Thursday.
So Tuesday was the 1st, Thursday is the 31st.
Checking my calendar, the next instance of this will be the year 2019.
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Posted by Jer
on 2017-01-09 13:41:41 |