30
18 numbers are there
40. Excluding numbers starting with 0.
There are 278 5-digit numbers less than 20,000 that are divisible by both four and nine.
How many two digit numbers are there in which the tens digit is greater than the oneβs digit ?
There is no limitation given to the number of digits in the number, thus: For 3 digit numbers: to be less than 500 the first digit can be only one of {1, 2, 3, 4} leading to 4 × 5 × 4 = 80 numbers For 2 digit numbers: they are all less than 500, and there are 6 × 5 = 30 numbers For 1 digit numbers: they are all less than 500, and there are 6 numbers Thus there are in total 80 + 30 + 6 = 116 numbers that can be made form the digits {1, 2, 3, 4, 5 ,6} without repetitions that are less than 500.
None. 3 digit numbers are not divisible by 19 digit numbers.
With a total of 90,000 five digit numbers, we can conclude that there is 45,000 EVEN five digit numbers.
There are five such numbers.
There are 21 two-digit prime numbers.
Five.The five numbers are 11, 12, 15, 24, 36
The answer will depend on how many digits there are in each of the 30 numbers. If the 30 numbers are all 6-digit numbers then the answer is NONE! If the 30 numbers are the first 30 counting numbers then there are 126 combinations of five 1-digit numbers, 1764 combinations of three 1-digit numbers and one 2-digit number, and 1710 combinations of one 1-digit number and two 2-digit numbers. That makes a total of 3600 5-digit combinations.
It would help to know which digit. 0 appears in 9 numbers and each of the others in 18 numbers.