Question

Case Study In a residential society comprising of 100 houses, there were 60 children between the ages of 10-15 years. They were inspired by their teachers to start composting to ensure that biodegradable waste is recycled. For this purpose, instead of each child doing it for only his/her house, children convinced the Residents welfare association to do it as a society initiative. For this they identified a square area in the local park. Local authorities charged amount of ₹ 50 per square metre for space so that there is no misuse of the space and Resident welfare association takes it seriously. Association hired a labourer for digging out 250 m3 and he charged ₹ 400 X (depth)2. Association will like to have minimum cost.

Total minimum cost of digging the pit (in ₹) is

Options

• 4,100

• 7,500

• 7,850

• 3,220

Answer 1

7,500

Explanation:

Total minimum cost,

`C = 12500/h + 400h^2`  ...(At 2.5)

`\implies C = 12500/2.5 + 400(2.5)^2`

`\implies` C = 5000 + 2500

`\implies` C = ₹ 7500