Put the elements in order from the highest electronegativity at the top of your list, to the lowest at the bottom. germanium (ge) gallium (ga) arsenic (as) bromine (br) rubidium (rb) selenium (se)

Br
Se
As
Ge
Ga
Rb
Elements in the top right corner of the periodic table have the highest electronegativity. Elements on the right side have a higher electronegativity than those on the left, same with the ones on the top in comparison to those on the bottom. 

29.1-12=17.1the answer is this one