write two quarters and a dime as a fraction of a dollar
They are 70/100, a fraction which can be simplified, if required.
There are 10 dimes in one dollar. One dime is one-tenth of a dollar.
1 dime/1 dollar = 10/100 = 1/10.1/10 is your answer.
A dime is 1/10 of a dollar. A nickel is 1/20 of a dollar.
It is 4/10.