Answer:
3ft:1in
Step-by-step explanation:
Given the clay model of a new car = 7in
If the actual car is 21ft, first we will have to convert 21ft to inches
Ift = 12in
21ft = x
x = 21×12.
x = 252in
21ft = 252in
This means that the clay model (7in) has to be scaled up to 252in. This is known as enlargement.
To know the scale of the model, we will take the ratio of the actual car to the clay as shown
Scale = actual car model/clay car model
Scale = 252/7
Scale = 36/1
We can also use the exact units of both measurement used in question
Scale = 21ft/7in
Scale = 3ft/1in
Hence the scale of the model is 3ft:1in