Answer:
3.6
Explanation:
We must first clarify how a number is rounded.
To round a number to unity we have to look at the first number after the comma.
If this number is less than 5 (1, 2, 3, 4) we should not do anything, but if that number is 5 or greater (5, 6, 7, 8, 9) we must add a unit to the number.
That is to say:
<5 do nothing
=> 5 round to the next number (+1)
So in the case of 3.55 it would be.
3.55 = 3.6