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1987 AMC 12/AHSME
3
Count the Primes
Count the Primes
Source:
March 27, 2006
arithmetic sequence
number theory
relatively prime
Problem Statement
How many primes less than
100
100
100
have
7
7
7
as the ones digit? (Assume the usual base ten representation)
(A)
4
(B)
5
(C)
6
(D)
7
(E)
8
\text{(A)} \ 4 \qquad \text{(B)} \ 5 \qquad \text{(C)} \ 6 \qquad \text{(D)} \ 7 \qquad \text{(E)} \ 8
(A)
4
(B)
5
(C)
6
(D)
7
(E)
8
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