Sherlock Homes and Dr

Sherlock Homes and Dr. Watson have to travel from Rajeev Gandhi chowk to Indira Gandhi International Airport via the metro. They have enough coins of 1, 5, 10 and 25 paise. Sherlock Homes agree to pay for Dr. Watson only if he tells all the possible combinations of coins that can be used to pay for the ticket. How many combinations are possible if the fare is 50 paise ?

Its source gives only the correct option, without the working.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #43022