Ratio of quarters to dimes.
A dime value = $0.10
A quarter value = $0.25.
Ratio of quarters to dimes = 0.25 : 0.10 = 25 : 1
And ratio of dimes to quarters will be
0.10 : 0.25 = 1:25.
We can see that 1:25 ratio is just reciprocal of 25:1.
We can just say that the ratio of quarters to dimes is reciprocal of the ratio of dimes to quarters.