Question

Find the cost (per kg) of each fertilizer A, B and C that a farmer needs to buy, such that 1 kg each of fertilizer A and C added to 2 kg of B costs him ₹ 400. Also, the cost of each kg of fertilizer B and C added together is equal to the cost of 1 kg of fertilizer A. However, the cost of 3 kg of fertilizer B added to ₹ 200 is the same as the cost of 1 kg of fertilizer A and C together. Use the matrix method to find the solution.

Hint:

To verify your solution quickly in a competitive exam, plug the calculated variables back into the simplest equation: $x - y - z = 150 - 50 - 100 = 0$. Since it satisfies the condition, your matrix inverse steps are guaranteed to be correct!

Answer 1