When overriding Object.Equals, is it appropriate to use the passed in object's Equals(MyType)?

When overriding Object.Equals, is it appropriate to use the passed in
object's Equals(MyType)?

For a simple example, assume you have two classes that are different in
many ways, but can still be considered "equateable":
class WholeNumber: IEquatable<WholeNumber> {
int value;
public override bool Equals(object obj) {
if (obj is IEquatable<WholeNumber>) {
IEquatable<WholeNumber> other = (IEquatable<WholeNumber>) obj;
return other.Equals(this);
} else {
return false;
}
}
public bool Equals(WholeNumber other) {
return this.value == other.value;
}
}
class Fraction : IEquateable<WholeNumber > {
WholeNumber numerator;
WholeNumber denominator;
public bool Equals(WholeNumber other) {
if (denominator != 1) {
// Assume fraction is already reduced
return false;
} else {
return this.numerator.Equals(other);
}
}
}
This will allow any object that claims to be equateable to WholeNumber to
be passed into the WholeNumber's Equals(object) function and get the
desired result without WholeNumber needed to know about any other class.
Is this pattern a good idea? Is using IEquatable with other classes a
common (where it makes sence) thing to do?