You didn't have the cash, so you borrowed 50K from your mom and 50K from your dad = 100K.
You bought the laptop which left you with 3K change.
You gave your dad 1K and ur mum 1K and kept the other 1K to yourself.
Now you owe your mum 49K and your dad 49K.
Now 49K+49K = 98K + your 1K kept = 99K.
Where is the missing 1K?
I know you are intelligent.
Solve it and tell us the answer.