HArd problem?

Jan 2007
26
0
A. Only once in American history has there been a decade (1790’s, 1940’s, etc.) in which four of the years (as four-digit numbers) were prime numbers. Find it.

B. Find the first decade (A.D.) in which all of the years were composite (non-prime) numbers. (Hint: America was not around then.)

Hey thanks for helping me out. your help is greatly appresciated!!!!!!!
 
Nov 2005
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New York City
A. Only once in American history has there been a decade (1790’s, 1940’s, etc.) in which four of the years (as four-digit numbers) were prime numbers. Find it.
I assume you want 1777 but 1 is not prime. There is no answer.

B. Find the first decade (A.D.) in which all of the years were composite (non-prime) numbers. (Hint: America was not around then.)
1 A.D.