Answer:
400^2 = 160 000
Explanation:
The sequence of perfect squares can be cosntructued by squaring the natural numbers.
That is, the first perfect square will be 1^2=2
the second will be 2^2 = 4
3rd - > 3^2 = 9
...
5 -> 5^2 = 25
...
300 -> 300^2 = 90 000
...
400 -> 400^2 = 160 000