Price of a diamond is proportional to the square of its mass which is measured in carat. Let 6 carat diamond piece be divided into two pieces. After division the total price of the two pieces is 5/8 of the original price. Determine the mass of the pieces.
Price of a diamond is proportional to the square of its mass which is measured in carat. Let 6 carat diamond piece be divided into two pieces. After division the total price of the two pieces is 5/8 of the original price. Determine the mass of the pieces. Correct Answer 4.5 and 1.5
Given:
Price of diamond ∝ square of mass
Calculation:
Let price of diamond be p and mass in carat be m
p ∝ m2 or p = km2 ----- (1)
Original mass = 6 carats
Original price = k × 36 = 36k From (1)
Let the mass of two pieces be x and 6 – x
Price of 1st piece = kx2
Price of 2nd piece = k(6 – x)2 = k (36 + x2 – 12x)
Total price of broken pieces = (5/8) × 36k = 45k/2
45k/2 = k (36 + x2 – 12x) + kx2
45 = 4x2 + 72 – 24x
4x2 – 24x + 27 = 0
4x2 – 18x – 6x + 27 = 0
2x (2x – 9) – 3 (2x – 9) = 0
x = 4.5 or 1.5
∴ The weights are 4.5 carats and 1.5 carats.