Very many countries use cents as their smaller denomination. Also, R25 could refer to any one of a number of currencies. If you cannot be bothered to be more specific in your question about the currencies that you are interested in then I am not going to try and guess and so cannot provide a more useful answer than this!
001 of a cent = 1 cent and you will need 100 of them to make a dollar.
2 COINS
Half of one.
two hundred and forty-five 245 x £0.10 = £24.50
The smallest coin available is a penny, worth one cent. Simply shift the decimal two places to the right (because you're going from dollars and cents to strictly cents) to find that you would need 2930 pennies to make $29.30 using the largest number of coins possible. Using any other coins would only decrease the number of coins in the combination.
20 cent coins
001 of a cent = 1 cent and you will need 100 of them to make a dollar.
Many countries have 20 cent coins and they are not all the same mass. So you need to be more specific when asking such questions and not assume that we can guess which country's currency you are referring to.
it's possible only if there are 20 cent coins only for that 7 dollars 1 dollar = 100 cents, 100 cents = 5 of 20 cent coins since you need 5 of 20 cent coins for a dollar, you do 7 times of it. 7 X 5 = 35. Therefore, you need 35 of 20 cent coins for 7 dollars. (or there are 35 of 20 cent coins in 7 dollars)
1 quarter and 1 dime.
2 COINS
There is a 2 cent euro coin, so to get 12 cents, you would need a 10 cent coin and a 2 cent coin.
You need 3 coins- the 50 cent piece, a dime, and a penny.
There are no 25p coins in circulation, however if there was you would need 20 x 25p to make £5.00
There are no 20cent coins. And you can't solve that question with the information given. You need the dimensions of the coins
Half of one.
The 50 cent coin was a necessary denomination between a 20 cent coin and One Dollar. Apart from it being half of a Dollar, it avoided the need to have a pocket full of 20 cent coins.