Question

Merian bought 1 kg of sugar she used 1/4 t bake a cake she has 3/8 remaining how much did she use to bake cake

Answer 1

3/8 what?
what is the density of sugar?

1 - 3/8 = 5/8

Maybe your vague question can be answered using the vague data provided above ...

Answer 2

Mere bought 10kg sugar she used 1/4 of it calculated the amount of sugar used