Where's hidden mistakes?

Question

The tests number one & seven aren't complete:

year = int(input())

if year%4==0:
print("Leap year")
else:
if year%100==0:
print("Leap year")
else:
if year%400==0:
print("Leap year")
else:
print("Not a leap year")

Answer 1

1700,1800,1900 aren't leap years , basically years divided by 400 are leap years so Not all years that get divided by 100 are leap years.

Answer 2

https://code.sololearn.com/cOgB9UfjI1vp

Answer 3

It is divided, isn't it ? 100 is a multiple of 4

Answer 4

То есть как бы выполнить проверку наоборот вопреки условию задания)

Answer 5

Так все эти годы делятся без остатка ???

Answer 6

Я не понимаю тогда в чем разница