It is your birthday and you want to buy a bottle of cheap whiskey for r97, since you don’t have cash

It is your birthday and you want to buy a bottle of cheap whiskey for R97, since you don’t have cash you borrow R50 from your dad and R50 from your mom. Now you have a R100. You purchase the cheap bottle for R97 and are left with R3 change. You return R1 to your dad and R1 to your mom and keep the R1 for yourself.
Now you owe your mom R49 and your dad R49.
Added together (R49 +R49 = R98) plus your R1 will = R99.

Where is the missing R1???

Tax man