Revenue at two shops — Caselets Aptitude Question
Revenue at two shops: Shop X sells 300 units at ₹40 each; Shop Y sells 250 units at ₹50 each. Answer and worked solution on CodeKairo.
- Topic: Caselets
- Section: Data Interpretation
- Difficulty: Medium
- Time target: 75 seconds
Question
Shop X sells 300 units at ₹40 each; Shop Y sells 250 units at ₹50 each. Both give a 10% discount on the listed price.
What is the combined revenue after the discount?
Options
- ₹20,250
- ₹21,150
- ₹22,050
- ₹24,500
Show the answer and the worked solution
Correct answer: C. ₹22,050
Worked solution
- Shop X gross = 300 × 40 = 12,000. Shop Y gross = 250 × 50 = 12,500.
- Combined gross = 24,500.
- After a 10% discount: 24,500 × 0.9 = ₹22,050.
Answer: ₹22,050.
The idea
When the same percentage applies to every part, apply it once to the total rather than to each part. Fewer multiplications means fewer chances to slip.
Shortcut. The gross is 24,500, and 90% of it is simply 9 × 2,450 = 22,050 — one single-digit multiplication instead of working out the discount and subtracting it.
Common trap. ₹24,500 is the combined gross before the discount; computing both shops' revenue correctly and forgetting the 10% gives it.