Answer :
Answer:
The American population was 20% of the British population.
Step-by-step explanation:
Let us call [tex]A[/tex] the american population, [tex]B[/tex] the British population before the migration, and [tex]x[/tex] the population that migrated from America to Britannia.
Now, the population [tex]x[/tex] that migrated was 20% of the american population:
[tex](1).\: \: x = 0.2A[/tex],
and the same population [tex]x[/tex] increase the British population by 4%:
[tex]x+B = 1.04B \\\\ (2). \:\:x = 0.04B.[/tex]
Combining equation (1) and (2) we get:
[tex]0.2A = 0.04B[/tex]
[tex]A = \dfrac{0.04B}{0.2}[/tex]
[tex]\boxed{A = 0.2B}[/tex]
Thus, the American population was 20% of the British population.