In yellow rays, stars A and B shine equally, and in red rays, star B is 0.1m brighter than star A. Which star is hotter?

As you know, the hotter the star, the shorter-wavelength region of the spectrum the maximum of its radiation falls. In our case, the spectrum of star B is dominated by long-wave (red) radiation, and if on the way from the Earth to these stars there is not a large amount of interstellar dust that absorbs the light of stars and changes its color, then star A is hotter than star B.