求教mathsjj289版-163T思路。。。储户存款题，拜谢！！

1.        DS：一个人对账户进行三种操作，存入500，取出300，或者取出400，问这个人本月操作次数是否超过10次？

（1）每种操作至少都进行了一次

（2）月末账户余额比月初多1600

（1）500a-300b-400cè不行

（2）500*4>1600è不行

C

这个题目拿到后就没有思路，看jj的解答也不明白说的什么意思，请教各位cder了。。。。周末就考了。。

i think its C or E depends on question

1 => 5x-3y-4z=something; x and y and z must be at least 1, can't explain

2 => can't explain

1+2 => x min is 6, y min is 2 and z min is 2....(6*5-2*3-2*4=16)

if question ask >= 10 then answer is C

if question ask > 10 then answer is E (because can be equal or larger than that)

JJ is pretty clear on this question

(1)+(2),

+500+500+(500+500-400-300)+(500+500-400-300)=1600,没有超过十

+500+500+(500+500-400-300)+(500+500-400-300)+[(500+500-400-300)-(500+500-400-300)]=1600,超过十