Difficulty: Easy
Correct Answer: 27 yr
Explanation:
Introduction / Context:Use the future absolute age to back out Indira's present age and the ratio multiplier, then compute Lizzy’s present and past ages.
Given Data / Assumptions:
Concept / Approach:Solve for k, derive Lizzy now, then subtract 5 years.
Step-by-Step Solution:
3k = 12 ⇒ k = 4Lizzy now = 8k = 32Lizzy 5 years ago = 32 − 5 = 27Verification / Alternative check:Indira now = 12, in 8 years = 20, consistent with the prompt.
Why Other Options Are Wrong:28, 37, 38 do not match the computed past age of Lizzy from the ratio and given future age.
Common Pitfalls:Using 20 as Indira’s present age or applying the 5-year subtraction to the wrong person.
Final Answer:27 yr.
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