Find the number of even factor of 90
Answers
Answer:
. 90 = 2 * 3* 3 * 5.
Step-by-step explanation:
A divisor of an integer n, also called a factor of n, is an integer which divides n without leaving a remainder. A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. A composite number is a positive integer that has at least one positive divisor other than one or itself. In other words a composite number is any positive integer greater than one that is not a prime number.
Literally prime means ‘of first importance’ and composite means ‘made up of various parts or elements’. Now what a composite number made up of? Prime numbers! All composite numbers can be written as a product of prime factors. This is called as the standard form of a composite number. We can say thatprime numbers are the basic building blocks of all numbers.
For example, 42 can be written as 2 * 3 * 7 and 50 can be written as 2 * 52
Always keep in mind that 1 is neither prime nor composite. But why 1 is neither prime nor composite?
In number theory, the fundamental theorem of arithmetic states that every integer greater than 1 is either prime itself or can be uniquely written as a product of prime numbers. Take the case of 90. Theorem states that 90 is either a prime or a product of primes. By factorization, we get 90 as product of primes. 90 = 2 * 3* 3 * 5. It also says that the combination of primes will be unique (if we disregard the order of primes). Means 90 can be written as 5 * 3 * 3 * 2 or 3 * 2 * 3 * 5 or any combination we can form using the prime. But there will be always one 2, two 3s and one 5 in the expression, which is unique to 90. If we treat 1 as a prime, then we can bring in any number of ones. We can write 90 as 5 * 3 * 3 * 2 * 1 and 5 * 3 * 3 * 2 * 1 * 1 which are both valid expression for 90 and this violate the unique factorization requirement of fundamental theory. So one is not considered as a prime and as one cannot be represented as a product of primes and hence one is not composite too
Answer:
90= 1,2,3,5,6,9,10,15,18,30,45,90
Even factors = 2,6,10,18,30,90 = 6