Final answer:
The total number of ways of selecting six coins out of 20 one-rupee coins, 10 fifty-paise coins, and 7 twenty-five coins can be found using combinations.
Step-by-step explanation:
The problem can be solved using combinations. We can select six coins out of 20 one-rupee coins, 10 fifty-paise coins, and 7 twenty-five coins.
To find the total number of ways, we can calculate the combinations of selecting six coins from each type of coin separately and then multiply the results together.
For the one-rupee coins, the number of ways to select six coins is C(20, 6). For the fifty-paise coins, the number of ways to select six coins is C(10, 6). And for the twenty-five coins, the number of ways to select six coins is C(7, 6).
Therefore, the total number of ways of selecting six coins from all the coins is C(20, 6) * C(10, 6) * C(7, 6). Calculate this to find the answer, which is option C.