If John has exactly 10 coins each of which was minted in 1910, 1920, or 1930, how many of his coins were minted in 1920?

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If John has exactly 10 coins each of which was minted in 1910, 1920, or 1930, how many of his coins were minted in 1920?

(1) Exactly 6 of his coins were minted in 1910 or 1920.
(2) Exactly 7 of his coins were minted in 1920 or 1930.

Answer: C

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VJesus12 wrote:
Fri Jan 28, 2022 7:27 am
If John has exactly 10 coins each of which was minted in 1910, 1920, or 1930, how many of his coins were minted in 1920?

(1) Exactly 6 of his coins were minted in 1910 or 1920.
(2) Exactly 7 of his coins were minted in 1920 or 1930
Statement 1:
Since 6 coins were minted in 1910 or 1920 -- and there are a total of 10 coins -- the number of coins minted in 1930 = 4.
No way to determine the number minted in 1920.

Statement 2:
Since 7 coins were minted in 1920 or 1930 -- and there are a total of 10 coins -- the number of coins minted in 1910 = 3.
No way to determine the number minted in 1920.

Statements combined:
Of the 10 coins, four were minted in 1930 and three in 1910.
Thus, the number of coins minted in 1920 = 10-4-3 = 3.
SUFFICIENT.

The correct answer is C.
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