You take 1/4 the total damage. You are looking at two separate events. The first event is whether or not you are hit with the 'full force' of the attack (your saving throw determines this). You can think of it like diving out of the way of a fireball, or ducking under a column of ice.
If you pass the saving throw, you take half (you successfully avoided some of the damage). If you don't, you take the full amount.
Now, after this, you resolve your resistances. From the Basic Rules, p75:
Damage Resistance and Vulnerability
Some creatures and objects are exceedingly difficult or unusually easy
to hurt with certain types of damage. If a creature or an object has
resistance to a damage type, damage of that type is halved against
At this point, you've already determined how much damage you were going to take due to your saving throw (either half or full). Now, you take the amount of damage you would have taken, and then take half of that because you have resistance to that damage type.