Help! Roundup/round down depending on cell value

[nicolam_83]

Hi all, this is the first time I've used this forum, so please bear with me while I try to explain what I need.

What I want is a formula for B1 and B2 which is 50% of A1 and A2 and if the value of A1 is not divisible by 2, but A2 is divisible by 2, then both B1 and B2 round up and vice versa. However, if neither A1 nor A2 are divisible by 2, i need B1 to round down and B2 to round up. Is this possible? I hope I've explained it clearly. Please see attachment. Thanks in advance for any advice.