How many odd factors does 210 have?

How many odd factors does 210 have?

Quiz

Answer/Solution

8

Steps/Work

Start with the prime factorization: 210 = 2*3*5*7
For odd factors, we put aside the factor of two, and look at the other prime factors.
set of exponents = {1, 1, 1}
plus 1 to each = {2, 2, 2}
product = 2*2*2 = 8
Therefore, there are 8 odd factors of 210. In case you are curious, they are {1, 3, 5, 7, 15, 21, 35, and 105}
Answer: E.