Income split (salary and tips): A driver's tips in a week were 5/4 of his salary. What fraction of his total income came from tips?

Introduction / Context:
This is a ratio-to-fraction conversion. Given a part (tips) relative to another part (salary), we first express both as parts of the whole, then compute the fraction for tips over total income.

Given Data / Assumptions:

• Let salary = S.
• Tips = (5/4)S.
• Total income = S + tips.

Concept / Approach:
Compute total = S + (5/4)S. Then tips fraction = tips / total. Simplify by factoring S and cancelling common factors.

Step-by-Step Solution:

Verification / Alternative check:
Pick a concrete S (e.g., 4). Tips = 5; total = 9; tips/total = 5/9. The fraction is independent of S, confirming the algebra.

Why Other Options Are Wrong:

• 4/9: Would correspond to tips being 4/5 of salary, not 5/4.
• 5/8: Ignores the correct total; 5/8 would mean total of 8 units with tips 5, but here total is 9 units (4 salary + 5 tips).
• 5/4: That is the ratio of tips to salary, not the fraction of total income.

Common Pitfalls:
Confusing ratio “of salary” with fraction “of total income.” Always compute the whole first, then form the desired part/whole fraction.

Final Answer: