Abuilding is 20 ft talk and cast a 12 foot shadow, and a person who is standing right next to the building cast a 3 ft shadow, how tall would the person be

5 ft

Step-by-step explanation:

The shadow of the person is 1/4 the length of the shadow of the building, so the person will be 1/4 the height of the building: 5 ft.

As this is college math, you would be expected to know that 3 ft × 4 = 12 ft, and 5 ft × 4 = 20 ft. You are also expected to know that shadow lengths are proportional to object heights.