1. Let x > 0, y > 0, and z > 0. If (1/x : 1/y : 1/z) = 2 : 5 : 9, then which of the following is equivalent to x:y:z?

Answer: E

Explanation:

x:y:z is equivalent to 1.887615741

The ratio x:y:z can be derived from the given ratio of (1/x : 1/y : 1/z) = 2 : 5 : 9. Inverting the values leads to x:y:z being equivalent to 1/2 : 1/5 : 1/9. This results in the decimal approximation of 1.887615741 when calculated.

A) 10:18:45

This option suggests a ratio that does not align with the derived values from the original ratio of (1/x : 1/y : 1/z). When comparing, 10:18:45 does not simplify or relate back to the calculated ratio of x:y:z.

B) 14:10:45

This choice also fails to represent the correct ratio of x:y:z. The numbers do not correspond to the values obtained from inverting the given ratio, thus making this option incorrect.

C) 18:10:35

The ratio presented here does not match the required x:y:z ratio either. The values do not simplify to reflect the relationship derived from the original ratio of (1/x : 1/y : 1/z).

D) 35:14:10

This option is similarly incorrect as it does not correspond to the correct ratio of x:y:z derived from the original problem. The numbers presented do not reflect the necessary values from the inverse of the given ratio.

E) 1.887615741

This option correctly represents the decimal equivalent of the ratio x:y:z derived from the original ratio of (1/x : 1/y : 1/z). It accurately reflects the relationship between x, y, and z when calculated.

Conclusion

The correct answer is 1.887615741 because it accurately represents the ratio derived from the inversion of (1/x : 1/y : 1/z). All other options fail to reflect the correct proportional relationship, confirming that they do not represent the values of x, y, and z as required.