The mass-to-light ratio of an object is the ratio of its mass to its luminosity. To calculate the mass-to-light ratio of a 1.1 Msun white dwarf with luminosity 0.001 Lsun, we need to divide the mass of the white dwarf by its luminosity. Since the mass of the white dwarf is 1.1 Msun and its luminosity is 0.001 Lsun, the mass-to-light ratio of the white dwarf is 1.1 Msun / 0.001 Lsun = 1100 Msun/Lsun.
To express the mass-to-light ratio using two significant figures, we need to round the result to the nearest multiple of 10. The nearest multiple of 10 to 1100 is 1100, so the mass-to-light ratio of the white dwarf is 1100 Msun/Lsun using two significant figures.