Answer:
Step-by-step explanation:
The trick here is when do the discounts take place? The "buy 1 get 1 half off" must take place before the total is computed to get the 20% off.
So she spends
First pair of socks: 20
Second Pair: 20 - 10 = 10
Hoodie: 20
Total: 50
Now she gets another 20% off which means that she still pays 80% of her purchases. (80 / 100) * 50 = 4000/100 = 40 dollars which is ultimately what she spent.
She saved a total of 10 + 10 = 20 dollars.
The % discount is (20 / 60 (which is what she should have paid) ) * 100
The % discount = 1/3 * 100 = 33.3 %