Answer: There is 1 quarter in the jar
Explanation:
First, we see that there needs to be at least one coin of each; a nickel, a dime, and a quarter.
5+10+25=40 (cents)
A quarter is worth 25 cents, and the total value is only 60, so it is impossible for the quarter value to be more than one, otherwise breaking the total value of 60 cents.