math #132, I think the answer is D

SC2000

討論稿是B
但是我算出來A is sufficient too.
b(100)+1 可以被5整除
b(100)+1 = b(99) +5 +1 (因為公差是5)
b(99)+1 +5 可以被5整除, 所以當然 b(99)+1 也可以被5整除拉.

so my answer is each one alone is sufficient.
any comments please?

mattybaby

题目是问：“问b（99）+1是否能被10整除”

SC2000

hahaha.... great, that was easy ......

港港

= =。