Answer:
100
Step-by-step explanation:
In this sequence, we can observe that the consistent change between each number in the series is divided by half.
From 400, we divide by 2 to get 200.
400 / 2 = 200
From 50, we divide by 2 to get 25.
50 / 2 = 25
So, to fill in the number after 200, we should logically divide by 2:
200 / 2 = 100
100 also fits into the following numbers, because 100 / 2 is 5.
