Where is the missing Ksh 1???

Question

I needed to buy a book that costed Ksh 97. My mum gave me Ksh 50 and dad Ksh 50. All became Ksh 100. I bought the book and got Ksh 3 back as balance. I returned back Ksh 1 to dad and Ksh 1 to mum and bought a sweet with the last Ksh 1. After returning Ksh 1 to dad and mum, they both end up having given me Ksh 49 each. Therefore 49(dad)+49(mum)+1(sweet) becomes Ksh 99. Where is the last Ksh to become Ksh 100??? (Ksh-Kenya Shillings)

Answer 1

49+49=98 if we give back add. 1Ksh then 49+48=97
97+3 (Ksh back)=100
1 Ksh hides I think in a bit tricky calculation
(48+1)+(49+1)+1=100
initial 48 and 49 to by a book
1 and 1 as cash back
1 to buy sweet

48+1(sweet)=49
(49+1(Ksh back))*2=100

Answer 2

ok
(50-1)+(50-1)-1=97
49+49-1=97
49+48=97

if count with total spent money that would be:
49+(48+1(sweet))=98
98+2(cashback)=100
so in some way yes they gave you 49Ksh each

Answer 3

Not really they both at first give 50. This is confusing