Given:
Principal (P) = 25000 rupees
Rate of interest (R) = 12%
Time (T) = 1 year
Now, Interest = P×R×T/100
=25000×12×1/100=300000/100
= 3000 rupees
Therfore, Amount = Principal + Interest
= 25000 + 3000
= 28000 rupees
Hence, Ahmed Chacha will have to return 28000 rupees to the bank at the end of the year.