Answer:
20-foot flag
Explanation:
12-foot flag casts 4.8-foot shadow,
which also means that:
4.8-foot shadow is casted by a 12-foot flag
Lets start by find the length of the flag that will cast a 1-foot shadow.
4.8-foot shadow -----> 12-foot flag
1-foot shadow -----> 12 ÷ 4.8 = 2.5-foot flag
Now we can find the flag that will cast a 8-foot shadow.
1-foot shadow -----> 2.5-foot flag
8-foot shadow -----> 8 x 2.5-foot = 20-foot flag