Difficulty: Easy
Correct Answer: 11
Explanation:
Introduction / Context:
Translate stepwise verbal operations into algebraic equations. First, recover the original number from the given condition. Then apply the new transformation and compute the final value exactly.
Given Data / Assumptions:
Concept / Approach:
Solve the first linear equation for N. Substitute that value into the second expression to obtain the requested result. Mixed-number options indicate that exact division may produce an integer or a fractional result, so compute carefully.
Step-by-Step Solution:
(N − 4)/6 = 9 → N − 4 = 54 → N = 58.Compute (N − 3)/5 = (58 − 3)/5 = 55/5 = 11.
Verification / Alternative check:
Plug back: (58 − 4)/6 = 54/6 = 9, matching the initial condition. The second calculation is straightforward division yielding an integer.
Why Other Options Are Wrong:
9 2/5, 10 1/5, 11 2/5, and 10 4/5 correspond to incorrect substitutions or arithmetic slips. Only 11 matches the correct evaluation.
Common Pitfalls:
Subtracting 3 from 9 instead of from N; mixing order of operations; performing 55/5 incorrectly as a mixed number.
Final Answer:
11
Discussion & Comments