10 chairs and 5 tables were purchased for Rs. 17,500. If the average cost of a…
2022
10 chairs and 5 tables were purchased for Rs. 17,500. If the average cost of a chair is Rs. 1,000, what is the average cost of a table?
Answer: D. Rs. 1,500 — ConceptWhen a group of items has a known average cost, its total cost equals the number of items multiplied by that average. The remaining amount after…
- A.
Rs. 1,400
- B.
Rs. 1,200
- C.
Rs. 1,100
- D.
Rs. 1,500
Attempted by 3 students.
Show answer & explanation
Correct answer: D
Concept
When a group of items has a known average cost, its total cost equals the number of items multiplied by that average. The remaining amount after subtracting one group’s cost is the total cost of the other group; dividing it by that group’s quantity gives its average cost.
Application
Cost of 10 chairs = 10 × Rs. 1,000 = Rs. 10,000.
Total cost of 5 tables = Rs. 17,500 − Rs. 10,000 = Rs. 7,500.
Average cost of one table = Rs. 7,500 ÷ 5 = Rs. 1,500.
Cross-check
Using Rs. 1,500 per table, the combined cost is 10 × Rs. 1,000 + 5 × Rs. 1,500 = Rs. 10,000 + Rs. 7,500 = Rs. 17,500, which matches the given total.
Therefore, the average cost of a table is Rs. 1,500.