Even numbers are formed by talking at least two at a time from the numbers 0, 4, 8, 9. Their H.C.F. is = ?

Explanation:-

Since all the numbers formed are even, 2 is a common factor.
Also, H.C.F. of two of the numbers i.e., 48 and 490, is 2.
So, the H.C.F. of all the numbers formed is 2.