a. 1/4 probably.
If that doesnt work then use the BEDMAS it might be as well way easier. That depends on how u think about it. So,
(1/2)
= 0.5 x 4
= ?
And ya. U can do that if it works properly.
Hope I helped u. And if this doesn't work, just go to google cuz it's a lot more better than me.
And again, I hope this is useful for u :)