Try to convert all of them, in one kind of unit, Here we will do for Kgs,
as we know, 1 kg = 1000 g
so, 2000g = 2 kg & 5050g = 5.050 Kg
Now, Arranging from smallest to greatest :
2 Kg < 3 Kg < 5.050 Kg < 75.75 Kg
In the end, you can re-replace the values, it would be:
2000 g < 3 Kg < 5050 g < 75.75 Kg
Hope this helps!