It depends on the denominations of the coins and the exchange rate at the time.
Two make combinations you would take 2x1=2 combinations only
720
20
42 combinations.
The answer will depend on which country's dollar, and therefore what he coins are. The US has a 25 cent coin but not a 20 cent coin. Australia is the other way around. There is no indication in the question which one you mean - if either. there are many more countries that use a dollar as their main currency unit.
10x1cent14x5cent2x10centOR15x1cent5x5cent6x10 centOR20x1cent4x5cent1x10cent1x50centThese are the ONLY combinations.
4 quarters or 10 dimes or 20 nickels or 100 pennies. One dollar is equal to 100 cents so many combinations of coins can be used.
Two make combinations you would take 2x1=2 combinations only
You can make a dollar with any sorts of combinations of coins. A dollar is 100 cents. So 4 quarters or 2 $.50 pieces or 10 dimes or 4 nickels +8 dimes.
You could make 10*10*10*26*26*26 combinations, or 17576000 combinations.
Assuming you are using the standard English alphabet, the number of combinations you can make are: 26 x 26 = 676 combinations.
9
23
8x7x6x5x4x3x2x1
The answer will depend on the country whose dollar you mean. Different countries, that use dollar, have coins of different denominations.
720
20