1956 AMC 12 Problem 31
Attempt Problem 31 of the 1956 AMC 12 below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 1956 AMC 12 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
31.
In our number system the base is ten. If the base were changed to four you would count as follows: The twentieth number would be:
Answer: E
Small hint:
The twentieth positive number represents the ordinary value
Big hint:
Divide successively by or express it using the place values and
Solution:
The twentieth positive integer has ordinary value Since its base-four representation is
Thus, the correct answer is E.