Contact us
Choose a category below so we can get back to you as quickly as possible.
用分步原理,先填個位(必為偶數)共有(0、2、4)三種可能,其中不為零(2、4)兩種,此時百位可選除(2或4和0)外其餘4个中的1個,十位可選除個位和百位数字外的4個数字中的一個,共有2×4×4=32,如果個位選0,則百位、十位...
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.