But since we cannot have 7 as a digit, we have 8 first digits and 9 second digits to choose from. Thus there are 8×9=72 two−digit numbers without a 7 as a digit. 90 (The total number of two−digit numbers)−72 (The number of two−digit numbers without a 7)=18⇒(B...
How many two-digit positive integers N have the property that the sum of N and the number obtained by reversing the order of the digits of N is a perfect square? 有多少个两位正整数 N 具有 N 与将 N 的数字顺序颠倒得到的数字之和是一个完全平方数的性质? A. 4 B. 5 C. 6 D. 7 E....
ELet N=10t +u,where t is the tens digit and u is the units digit.-|||-The condition of the problem is that 10t +u 10u +t is a perfect square.-|||-Simplifying and factoring,we want 11(t +u)to be a perfect square.-|||-Thus,t u must at least be a multiple of 11,and...
2【题目】How many two-digit positive integers are there suchthat the sum of the two- digit positive integer and the number formed by reversing the digits of the two-digit positive integer is a square number?有多少个两位正整数,使得两位正整数与两位正整数的数字对位所形成的数之和是平方数?A.5B...
气教便入亲资们感书运How many two-digit positive integers contain at least one digit equal to 气教
1How many two-digit positive integers are there such that the sum of the two- digit positive integer and the number formed by reversing the digits of the two-digit positive integer is a square number?有多少个两位正整数,使得两位正整数与两位正整数的数字对位所形成的数之和是平方数? A.5 B....
题目 How many two-digi tpositiv einteger sca nbe written using only even numbers?() A.16 B.20 C.25 D.50 答案 B。 结果二 题目 How many two-digit positive integers can be written using only even numbers?( )A.16B.20C.25D.50 答案 B相关推荐 1How many two-digi tpositiv einteger sc...
谁给翻译下,英文的,当天就给分 how many positive two-digit integers can be made from the digits(3,
How many 2-digit positive integers are there such that the product of their two digits is 24 ? AOne BTwo CFour DSix EEight 显示答案 后才可以添加做题笔记哦,还没有账号?马上注册 KMF 解析 网友解析 题目数据 收起 暂无解析 以上解析由考满分老师提供。
For any positive integer n, the length of n is defined as the number of prime factors whose product is n. For example, the length of 75 is 3, since 75 = 3 × 5 × 5. How many two-digit positive integers have length 6 ?_出国考试答疑器_