Answer :
Half of 2 = 1 so 1 year apart . That means
80-1 = 79 years
80-1 = 79 years
if u were 2 years old n your sister was half your age then her age must be 1
so her present age is 80-1=79(since she was just one year smaller than u)
so her present age is 80-1=79(since she was just one year smaller than u)