AMC8 1991

AMC8 1991 · Q1

AMC8 1991 · Q1. It mainly tests Arithmetic misc.

$1,000,000,000,000 - 777,777,777,777 =$

$1,000,000,000,000 - 777,777,777,777 = $

(A) 222,222,222,222 222,222,222,222

(B) 222,222,222,223 222,222,222,223

(D) 322,222,222,223 322,222,222,223

(E) 333,333,333,333 333,333,333,333

Answer

Correct choice: (B)

正确答案：（B）

Solution

Write the problem vertically and compute the difference: $1,000,000,000,000 - 777,777,777,777 = 222,222,222,223$ OR What must be added to $777,777,777,777$ to get $1,000,000,000,000$? From the right, one adds a final digit of 3 and then eleven 2’s.

将问题竖式书写并计算差：$1,000,000,000,000 - 777,777,777,777 = 222,222,222,223$ 或什么数加到 $777,777,777,777$ 上得到 $1,000,000,000,000$？从右边开始，加一个尾数 3，然后是十一个 2。

Topics

AR.015 Arithmetic misc