If the cost of x metres of wire is d rupees, what is the cost of y metres at the same rate?

Given data

• Cost for x m = d rupees
• Find cost for y m at same unit rate

Concept / Approach

• Unit rate = (cost per metre) = d/x rupees per metre.

Step-by-step calculation

Cost for y m = (d/x) × y = (dy)/x rupees

Verification

For y = x, formula gives d rupees, consistent.

Common pitfalls

• Using dx/y (that would be cost for x/y metres).

Final Answer

dy/x rupees