Quadratic Equations
Work-Rate Problem — Quadratic in Days
nta_pyq_2026_jan
Grade 11
Question:
A building construction work can be completed by two masons A and B together in 22.5 days. Mason A alone can complete the construction work in 24 days less than mason B alone. Then mason A alone will complete the construction work in:
30 days
36 days
24 days
42 days
Step-by-Step Solution
Key Concept: Let A take $a$ days, B takes $a+24$ days. $\tfrac{1}{a}+\tfrac{1}{a+24}=\tfrac{1}{22.5}=\tfrac{2}{45}$.
Mason A alone: 36 days.
Correct Answer: 2