How many positive 3-digit integers contain only odd digits?
Any decimal that has a finite number of nonzero digits is a terminating decimal. For example, 16, 12.43, and 0.26 are all terminating decimals. If a and b are positive integers and the ratio a/b is expressed as a decimal, is a/b a terminating decimal?
(1) b=5
(2) 70<80
How many different four-digit integers can be formed using the digits 3, 4, 5, 6, 7, 8, 9 if the tens digit is 5 and no digit is repeated within an integer?
1, 2, 6, 7, 9
A three-digit integer is to be formed from the digits listed above. If the first digit must be odd, either the second or the third digit must be 2, and no digit may be repeated, how many such integers are possible?
How many four-digit numbers have only even digits?
在python中,string模块有digits属性。
在python中,如想自动生成数字,可使用string中digits属性。
digits属性可以生成下列哪些元素?()