Hi
To compare two fractions, you have to make them at same denominator.
As we have 3 and 5 , and 15 is common to both 3 and 5 as 3*5 = 15 , I will convert both fraction in order to have fraction where 15 is denominator.
How to do so ? well, I multiply both numerator and denomintator of -1/3 by 5 and numerator and denomintator of -2/5 by 3
So we have : -1/3 = -1*5 / 3*5 = -5/15
So we have : -2/5 = -2*3 / 5*3 = -6 / 15
Now as both fraction have same denominator, I check which numerator is the greater.
Remember that greater for a negative number means : which one is closest to 0.
If you have trouble to remember that, just imagine that numbers are on a vertical line, or like storey in a skyscrapper. ( and 0 is street floor )
If you are at storey -5 , are you above or under storey -6 ? near the ground , or deeper in basement ?
If you are above, then number is greater. If you are under, then number is smaller.
Well , -5 is closer to 0 than -6 ,
so -5/15 ≥ -6/15
so -1/3 ≥ -2/5