Let the length on drawing for actual length of 15 ft = x inches
And they say that the ratio of drawing length to actual length is 0.25 in : 12 ft
it means we can make a ratio proportion such that
[tex] \frac{0.25_{in} }{12_{ft}} = \frac{x {in}}{15_{ft}} [/tex]
Cross multiplying we get
0.25 * 15 = 12*x
3.75 = 12 x
Divide both sides by 12
x = 0.3125
It means
the length on drawing for actual length of 15 ft = 0.3125 inches