It is not the same .
It is not the same because after doing the 25% the first time you will get a different number to be multiplied by 25%. But with 50% you only do it once to one number only
50%:
100 x 0.5= 50
100-50= 50
final price: $50
25% then another 25%:
discount off original price
100 x .25= 25
100-25= 75
discount off sales price
75 x .25=18.75
75-18.75= 56.25
final price $ 56.25
AS you can see it is not the same