So, there are 1, 5, 10, 25 and 50 cent coins.
The most logical combination would be a dime and a quarter (10 + 25 = 35) but it is said that "one of the coins is not a dime".
But, there is something many people don't notice. It says that one of the coins isn't a dime, but the other one can be a dime. So, the two coins are a quarter and a dime.
Hope it helped,
BioTeacher101
