Eduardo thinks of a number between 1 and 20 that has exactly 5 factors. What number is he thinking of? | Socratic Eduardo thinks of a number between 1 and 20 that has exactly 5 factors. What number is he thinking of? It is apparent that a number cannot be a prime number, if it has exactly 5 factors. So it is among {4,6,8,10,12,14,16,18,20}
Are there any numbers that have 5 factors?
Any number that is p^4 (^ means exponent; p * p * p * p), where p is a prime number, will have five factors. For example, 2 is a prime and 2^4 = 16, which has the 5 factors: 1, 2, 4, 8, 16… Loading… Most numbers have even number factors because the factors come in pairs. For example, the number 12 has 6 factors: 1, 2, 3, 4, 6, 12.
How many numbers from 1 to 100 have exactly 3 factors?
The factors must be prime, since any non-prime factor would itself have factors, meaning we’d exclude for example 2 x 3 x 4 = 24 since 4 is 2 x 2, so 24 really has 4 factors. Prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23 – anything over this cannot result in a combined result of 100 or less (since 2 x 2 x n = 100 gives n = 25).
What are two numbers less than 50 that have exactly 3 factors?
You should have probably mentioned “2 digit numbers less than 50 that have exactly 3 factors”, because this is the property of a square number of a prime and there are 4 squares below 50 that are the squares of prime numbers. There are 4 numbers as shown below and two of them are 2 digit numbers and the remaining 2 numbers are single digit numbers.
Which is the largest number with 5 factors?
It would seem that the largest one is most likely to have 5 factors, so let’s look at 16 first. Factors of 16: 1, 2, 4, 8, 16 ← there are 5 factors! As a check, let’s consider the other squares: 1 has only 1 factor.
How many factors are there in the number 16?
Factors of 16: 1, 2, 4, 8, 16 ← there are 5 factors! As a check, let’s consider the other squares: 1 has only 1 factor.
How do you find the factor of 2?
Factoring is the process of multiplying two numbers to get an original number. For example, to find the factor of 2 we solve it using multiplication. That is, 1 x 2 = 2, where 1 and 2 is the factor of 2. Become a Study.com member to unlock this answer!
