结果1 题目 How many 2−digit numbers are there such that the sum of the digits is divisible by 3 and no repeated digits are used?有多少个数位之和是3的倍数且没有重复数位的两位数? 相关知识点: 试题来源: 解析 27. 反馈 收藏 ...
How many three−digit numbers are not divisible by 5, have digits that sum to less than 20, and have the first digit equal to the third digit?( ) A.52 B.60 C.66 D.68 E.70相关知识点: 试题来源: 解析 B These three digit numbers are of the form xyx. We see that x≠0 and ...
To test if a number is divisible by three, you add up the digits of the number. If the sum is divisible by three, then the original number is a multiple of three. If the sum is too large, you can repeat the process until you can tell whether it is a multiple of three. This is...
(1) How many different digits can be filled in the square so that ¯¯¯¯¯¯¯¯¯¯28□ is divisible by both 2 and 3? (2) How many different digits can be filled in the square so that ¯¯¯¯¯¯¯¯¯¯22□ is divisible by both 3 and 5?相...
12. How many three-digit positive integers N satisfy the following properties?●The number N is divisible by 7.●The number formed by reversing the digits of N is divisible by 5.满足以下性质的三位正整数N有多少个?●数N可以被7整除。
How many 4-digit positive integers (that is, integers between 1000 and 9999, inclusive) having only even digits are divisible by 5?在4位正整数(即1000和9999之间的整数 ·包括1000和9999)有多少个数满足每一位数都是偶数,并且可以被5整除?
How many three-digit numbers have a sum of digits not divisible by 7?相关知识点: 试题来源: 解析 774. 设三位数abc的百位,十位,个位上的数字分别为a,b,c,则1⩽a⩽9,0⩽b⩽9,0⩽c⩽9,且a,b,c均为整数, 最小的三位数是100,最大的三位数是999,则三位数有999−100+1=900个, ...
How many 4-digit numbers, which is divisible by 33, can be formed by using 1, 2, 3, 4, 5 and 6 with no repeating digits?相关知识点: 试题来源: 解析 16. 设该四位数为 ¯¯¯¯¯¯¯¯¯¯abcd, 若¯¯¯¯¯¯¯¯¯¯abcd 能被33整除, 即a+c=b+...
1. Suppose repetitions are not allowed (a) Find the number n of three-digit numbers that can be formed from the six digits: 2,3,5,6,7,9. (b) How many of them are even? (C) How many of them excee How is the mean square computed from the sum of squares?
解析 One thing to remember is that a number is divisible by 3 if the sum of all its digits is divisible by 3.Since 0 is not allowed and removing any one of the 4 digits results in a number divisible by 3,t...结果一 题目 How many four-digit numbers containing no zeros have the ...