AMC8 1992

AMC8 1992 · Q7

AMC8 1992 · Q7. It mainly tests Parity (odd/even), Digit properties (sum of digits, divisibility tests).

The digit-sum of 998 is 9 + 9 + 8 = 26. How many 3-digit whole numbers, whose digit-sum is 26, are even?

998 的数位和是 9 + 9 + 8 = 26。有多少个三位整数的数位和是 26 且是偶数？

(A) 1 1

(B) 2 2

(D) 4 4

(E) 5 5

Answer

Correct choice: (A)

正确答案：（A）

Solution

The only 3-digit whole numbers with a digit-sum of 26 are 899, 989 and 998. Of these, only 998 is even. Thus there is only one such number.

数位和为 26 的唯一三位整数是 899、989 和 998。其中只有 998 是偶数。因此只有一个这样的数。

Topics