Chained percentages into a three-term ratio: Salary of Mr. X is 80% of Mr. Y’s salary, and salary of Mr. Z is 120% of Mr. X’s salary. What is the ratio X : Y : Z? Select the correct option or “None of these” if no option matches.

Introduction / Context:
Converting chained percentage relationships to a direct ratio requires expressing each person’s salary in terms of a single base (here, Y). Then scale to integers and compare with the given options. If none match, “None of these” is appropriate.

Given Data / Assumptions:

• X = 80% of Y ⇒ X = 0.8Y.
• Z = 120% of X ⇒ Z = 1.2X.

Concept / Approach:
Substitute X into Z to express all in terms of Y, then read off X : Y : Z and simplify. Compare with the listed choices.

Step-by-Step Solution:

Verification / Alternative check:
20 : 25 : 24 equals 0.8 : 1 : 0.96. Comparing to options shows no exact match; thus “None of these”.

Why Other Options Are Wrong:
4 : 5 : 6 corresponds to 0.8 : 1 : 1.2 (Z too large). Other options similarly fail to represent Z = 0.96Y.

Common Pitfalls:
Assuming Z is 120% of Y directly or mis-scaling decimals when converting to integers.

Final Answer:
None of these