Attached the solution and work.
Hello!
1 minute 3 seconds = 63 seconds
We must found out 63 is 90% of what number, using the percentage formula:
90 * 100 / 63 = 70
70 seconds = 1 minute 10 seconds
So, Niki's time for one lap is 1 minute 10 seconds (70 seconds).
Answer:
The American population was 20% of the British population.
Step-by-step explanation:
Let us call
the american population,
the British population before the migration, and
the population that migrated from America to Britannia.
Now, the population
that migrated was 20% of the american population:
,
and the same population
increase the British population by 4%:

Combining equation (1) and (2) we get:



Thus, the American population was 20% of the British population.