1987 AMC 8 Problem 8
Attempt Problem 8 of the 1987 AMC 8 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 1987 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
8.
In the addition problem below, and are nonzero digits:
How many digits (not necessarily different) are in the sum of the three whole numbers?
depends on the values of and
Answer: B
Small hint:
The number is already close to so adding anything pushes the sum past it
Big hint:
Check the largest possible sum too, using
Solution:
Since and are at least the sum is at least which has digits.
At the other extreme, with the sum is still digits. So the sum always has exactly digits.
Thus, the correct answer is B .
Problem 8 in other years
- 1985 AMC 8
- 1986 AMC 8
- 1988 AMC 8
- 1989 AMC 8
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