How many 3-digit numbers are there so that the sum of its digits is 5?有多少个三位数的各个数字之和是5? 答案 15个.各个数字之和为5,百位是1的三位数有104、113、122、131、140;百位是3的三位数有203、212、221、230;百位是3的三位数有302、311、320;百位是4的三位数有401、410;百位是5的三位...
所以有8种选择, 一共可以组成9×9×8=648个没有重复数字的三位数.结果一 题目 没有重复数字的三位数有多少个?How many three-digit numbers are there with no repeating digits? 答案 648.相关推荐 1没有重复数字的三位数有多少个?How many three-digit numbers are there with no repeating digits?反馈...
To find how many three-digit numbers can be formed with no repeated digits, we can break the problem down into steps based on the placement of the digits.1. Identify the Structure of a Three-Digit Number: A three-digit numbe
How many 3 digit numbers are there such that the sum of the digits is 17?Writing Simple Equations.Writing simple equations with certain constraints is an easy task to do if we can figure out which digit has which constraints. Certain constraints to keep in mind while solving ...
Answer to: How many three-digit numbers are there with 3 in the unit place? (i) with repetition. (ii) without repetition. By signing up, you'll get...
How many three-digit numbers are there that have the sum of their digits equal to 10?. 相关知识点: 试题来源: 解析 54.. When the hundred digit is 1:109,118,127,⋯,190,there are 10 numbers; when the hundred digit is 2:208,217,226,⋯,280, there are 9 numbers; when the ...
17.有多少个三位数,其各位数字的乘积是质数 17. How many three-digit numbers are there such that(注:1不是质数)? the product of their digits is a prime number?(A)15 (B)12 (C)17 (Remember 1 is not a prime number.)(D)20 (E)21 (A)15 (B)12 (C)17(D)20 (E)21 答案 17.B相...
There are total 10 digits from 0 to 9. :' The numbers cannot starts from 0. So, numbers of ways of filling first place = 9 Number of ways of filling second place = 9 Number of ways of filling third place = 8 Number of ways of filling four place
How many four digit numbers are there in all? View Solution How many 4-digit numbers are there when a digit may be repeated an number of times? View Solution How many six-digit numbers are there in which no digit is repeated, even digits appear at even places, odd digits appear at odd...
第一位数：9种 (10种中减去0）第二位：10种-1种（第一位里选走的）第三位：9种-1种（10个数选走了2）