Answer:
GCF of 256 and 400 is 16.
Explanation:
We have to find GCF that is the greatest common factor of 256 and 400.
We would use prime factorization that is breaking the number in the form of product of prime numbers. Then, in order to calculate greatest common factor, we multiply the common prime factors of both the numbers.
![256 = 2^8 = 2* 2* 2* 2* 2* 2* 2* 2\\400 = 2^4* 5^2 = 2* 2* 2* 2* 5* 5](https://img.qammunity.org/2019/formulas/mathematics/middle-school/4ryxbkjueu8h56b7lopp5rkqw9wslxsfl2.png)
Common factor:
![256~ \&~ 400 = 2* 2* 2* 2 = 16](https://img.qammunity.org/2019/formulas/mathematics/middle-school/fkpfgb5y3s9q3umc1c9olxl5aze2166xsi.png)
Hence, GCF of 256 and 400 is 16.