You get $50 from your mom and $50 from your dad. You buy a shirt for $97 and get $3 change.
You give $1 back to your mom and $1 back to your dad and keep $1 for yourself. Now you owe your mom and dad $49 dollars each.
So sum it up, $49 x 2 = $98 + the $1 you kept = $99.
you have 50+50=100, 100-97=3, so 100-3=97, (100-2)-1=97, 98-1=97 your error is here you say 98+1=99 not 98-1=97.
Makes sense. Nice one
definitely made me think though