Problem 1
A = 984 ft = height of the tower in real life
B = 328 ft = width of the tower in real life
C = 12 in = height of the scale model
D = unknown = width of the scale model
A/B = C/D
(984 ft)/(328 ft) = (12 inches)/(D inches)
984/328 = 12/D
984D = 328*12
D = 328*12/984
D = 4
Answer: 4 inches is the width of the scale model
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Problem 2
A = 4 cm = some distance on the map corresponding to B
B = 20 km = the corresponding real life distance to A
C = unknown = some distance on the map corresponding to D
D = 82 km = real life distance corresponding to C
A/B = C/D
(4 cm)/(20 km) = (C cm)/(82 km)
4/20 = C/82
4*82 = 20C
C = 4*82/20
C = 16.4
Answer: Exactly 16.4 cm