1992 AMC 8 Problem 7

Attempt Problem 7 of the 1992 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 1992 AMC 8 solutions, or check the answer key.

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7.

The digit-sum of 998998 is 9+9+8=26.9 + 9 + 8 = 26. How many 33-digit whole numbers, whose digit-sum is 2626, are even?

11

22

33

44

55

Answer: A
Concepts:digitsparity

Difficulty rating: 900

Solution:

A digit-sum of 2626 with three digits requires the digits 9,9,8.9, 9, 8. The 33-digit numbers using them are 899,989,899, 989, and 998.998.

Of these, only 998998 is even, so there is exactly 11 such number.

Thus, the correct answer is A .

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