21:3
9:3
3:1
there all a 3:1 ratio
Step-by-step explanation:
Derive an expression for the equivalent width in a saturated line. Assume a Voigt profile, with the difference in optical depth between the center of the line and the wings being ~104. The wings of the line can be ignored. Define a frequency x1 = (v1 − v0)/ΔvD, where the optical depth τv = 1. Inside of x1 the line is fully saturated, and outside x1 the line is optically thin. Show that the equivalent width is

Note that the equivalent width is practically insensitive to the number density of absorbing material.
20 because when you divide 12 by 3/5 you get 20 use a calculator
It would be: 32/48 = 16/24 = 8/12 = 4/6 = 2/3
[ Just try to divide numerator & denominator by 2, until they reach at the position, when they can't reduce anymore ]
In short, Your Answer would be 2/3
Hope this helps!
