Find the quantity of salt costing Rs.8.50 per kg should be mixed with 60 kg of salt at a rate of 11.60 per kg to obtain a mixture worth Rs.9 per kg11.4511.9613.6511.53

The problem is asking to find the quantity of salt costing Rs.8.50 per kg that should be mixed with 60 kg of salt costing Rs.11.60 per kg to obtain a mixture worth Rs.9 per kg.

Let's denote the quantity of salt costing Rs.8.50 per kg as x kg.

The total cost of the 60 kg salt at Rs.11.60 per kg is 60 * 11.60 = Rs.696.

The total cost of the x kg salt at Rs.8.50 per kg is x * 8.50.

The total weight of the salt mixture is 60 + x kg and the total cost of the mixture is Rs.9 per kg, so the total cost is (60 + x) * 9.

According to the problem, the total cost of the 60 kg salt and the x kg salt is equal to the total cost of the mixture. So we can set up the following equation:

60 * 11.60 + x * 8.50 = (60 + x) * 9

Solving this equation will give us the value of x.

696 + 8.5x = 540 + 9x

Subtract 8.5x from both sides:

696 = 540 + 0.5x

Subtract 540 from both sides:

156 = 0.5x

Finally, divide both sides by 0.5 to solve for x:

x = 156 / 0.5 = 312 kg

So, 312 kg of salt costing Rs.8.50 per kg should be mixed with the 60 kg of salt costing Rs.11.60 per kg to obtain a mixture worth Rs.9 per kg.