訂購 Herman Yeung 數學天書詳情

2016年5月24日 星期二

疑似 HKMO 題目 3































































連結 Link:   IQ 題 (主頁)

連結 Link:   Herman Yeung Blog 主目錄


8 則留言:

KH Tang 提到...

C is not possible to be 8 as 58 is not divisible by 4.

Herman Yeung 提到...

係喎,計多左。

Unknown 提到...

By considering the combination,
225 = 3²×5²:3×3 = 9
255 = 3×5×17:2×2×2 = 8
...

Herman Yeung 提到...

已 updated, thanks

Herman Yeung 提到...

thanks a lot, 我都覺得我的方法好慢,原來真係有更快的方法
多謝您。

Unknown 提到...

不用謝:)
請問這三題會否上傳至 Youtube ?

Herman Yeung 提到...

可能會,之後拍 HKMO 時可能會再做一次呢題

匿名 提到...

Consider the condition (d) which implies that CBA must be a perfect square number. (Factors are in pairs, only exception is a square number. Odd number of factors imply which is a perfect square)
Obviously, A=5. There are only two square numbers 15^2=225 and 25^2=625 which are in between 100-999. As only 2+2+5=3*3, CBA=225 and ABC=522