The price of a wire made of a superalloy material is proportional to the square of its length
Q. The price of a wire made of a superalloy material is proportional to the square of its length. The price of 10 m length of the wire is Rs. 1600. What would be the total price (in Rs.) of two wires of lengths 4 m and 6m?
(A) 768 (B) 832 (C) 1440 (D) 1600
Ans: 832
The price of wire made of super alloy material is proportional to the square of its length.
Price × (length)2
Price = k × l2
Length of wire = 10 m
According to given condition,
1600 = k (10)2 ⇒ 1600 = k (100) ⇒ k = 16
So that price of two wires of length 4 m and 6 m is = k [l21 + l22] = 16[42 + 62]
Total cost = 832