4, 6, 8 or 9
The smallest three digit composite number is 100, and the largest two digit number is 99. 100-99=1.
It is: 9
4/4 = 1
9
The least 1 digit number that is composite is 4. It is because all numbers before that are prime.
The ratio of the number of one-digit prime numbers to the number of one-digit composite numbers is one to one. The one-digit prime numbers are 2, 3, 5, and 7. The one-digit composite numbers are 4, 6, 8, and 9. Therefor, the ratio is 4:4, which simplifies to 1:1.
least two-digit composite number = 11
The largest 2 digit composite number is 99.
4 is the least one digit composite number
42 is composite, 43 is prime.
The largest single digit composite number is 9. The largest prime number is 17 million digits long. The definition of a composite number is any number that has at least one positive divisor other than one or the number itself (it is not a prime number). The largest composite digit is therefore longer than the largest prime number by at leaf +1.
100 is the lowest 3-digit number and it is composite, so 100 is your answer.