AMC8 2005

AMC8 2005 · Q12

AMC8 2005 · Q12. It mainly tests Arithmetic sequences basics.

Big Al, the ape, ate 100 bananas from May 1 through May 5. Each day he ate six more bananas than on the previous day. How many bananas did Big Al eat on May 5?

大猩猩 Big Al 从 5 月 1 日到 5 月 5 日吃了 100 根香蕉。每天他比前一天多吃 6 根香蕉。Big Al 在 5 月 5 日吃了多少根香蕉？

(A) 20 20

(B) 22 22

(D) 32 32

(E) 34 34

Answer

Correct choice: (D)

正确答案：（D）

Solution

(D) You can solve this problem by guessing and checking. If Big Al had eaten 10 bananas on May 1, then he would have eaten $10 + 16 + 22 + 28 + 34 = 110$ bananas. This is 10 bananas too many, so he actually ate 2 fewer bananas each day. Thus, Big Al ate 8 bananas on May 1 and 32 bananas on May 5.

(D) 你可以通过猜测并检验来解决这个问题。如果 Big Al 在 5 月 1 日吃了 10 根香蕉，那么他一共会吃 $10 + 16 + 22 + 28 + 34 = 110$ 根香蕉。这就多了 10 根，所以他实际上每天都少吃 2 根。因此，Big Al 在 5 月 1 日吃了 8 根香蕉，在 5 月 5 日吃了 32 根香蕉。

Topics

AR.012 Arithmetic sequences basics