even numbers end with 0,2,4,6,8
7 in hundreds place
odd in thousands place, odd numbers are 1,3,5,7,9
multiplue of 10 end with 0
so therfor the number has 7 in hundreds place and ends with 0 with odd in thousands and undefined hundreds place
50 options
some examples are
1730
9790
any number, x7y0 such that x is odd and y can be any number
