Answer: B. (1/200 = x/19.5)
EXPLANATION
Space shuttle Atlantis model scale 1:200
Length of Atlantis on model = 19.5
The actual length of Atlantis = x
Find x
Scale = 1:200; in decimal = 1/200
When length on model = 1
Actual length = 200
When actual length = x
Length on model = 19.5
Scale = x:19.5 ; in decimal = x/19.5
Equating both scales,
1/200 = x/19.5 (Option B)
