So the total number of threedigit numbers that satisfy the property is . Alternatively, we could note that the middle digit is uniquely defined by the first and third digits since it is half of their sum. This also means that the sum of the first and third digits must be even. Since ...
Find the number of 3-digit numbers, formed with the digit (2,5,4,6) when repetition of the digits is allowed.
计算由奇数数字组成的3位正整数的数量N,并与125(Quantity B)比较。 **步骤拆解** 1. **确定条件**: - 三位数的百位不能为0,且所有位(百位、十位、个位)均为奇数数字(即1, 3, 5, 7, 9)。 2. **计算每一位置的选项**: - **百位**:可选的奇数为5种(1, 3, 5, 7, 9)。
Find the number of 6-digit numbers of the form ababab (in base 10) each of which is a product of exactly 6distinct primes. View Solution The total number of 3-digit numbers, whose sum of digits is 10, is View Solution Knowledge Check The sum of all the 3 digit numbers is A98901...
1What is the total number of different 5-digit numbers that contain all of the digits 2,3, 4, 7 and 9 and in which none of the odd digits occur next to each other? A. 12 B. 10 C. 8 D. 6 E. 1 2What is the total number of different 5-digitnumbers that contain all of ...
natural numbers, such that the first natural number plus 5, the second natural number minus 5, the third natural number multiplied by 5, the fourth natural number divided by five, are all equal. Then the sum of all the three-digit numbers satisfying the above conditions is ( ). ...
Answer to: The units digit of a three-digit number is prime. The hundreds digit is twice the tens digit. How many of these three-digit numbers are...
18. How many odd 3-digit numbers have the property that their digits, read left to right, are in strictly increasing order? 相关知识点: 试题来源: 解析 解:符合要求的三位数的十位数字只能是2~8,下面进行分类计数。 (1)口2口的有1 ×4=4(个); (2)口3口的有2 ×3=6(个); (3)口4口...
There are (35)2 cdot 30 leaves on a tree. What is the total number of leaves on the tree? There are (3^5)^2 - 3^0 leaves on a tree. What is the total number of leaves on the tree? On the first day of vacation, you read one-third of novel. On...
to calculate B. B=Total - A - CTotal numbers from 700 to 999 = 299 (3-digit numbers ...