2015 AMC 12B Problem 3
Attempt Problem 3 of the 2015 AMC 12B 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 2015 AMC 12B solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
3.
Isaac has written down one integer two times and another integer three times. The sum of the five numbers is and one of the numbers is What is the other number?
Answer: A
Small hint:
Let appear twice and appear three times, so
Big hint:
Test whether is the number written two times or three times, and keep the integer case
Solution:
Write If were written twice, then which is not a multiple of
So is written three times: giving
Thus, the correct answer is A.
Problem 3 in other years
- 1950 AMC 12
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