Let's solve each part of the question step-by-step.
### Part (i):
We are given that the cost of 8 kg of grapes is Rs 960. We need to find the cost per kilogram of grapes.
To find the rate of cost per kg, we divide the total cost by the weight in kilograms.
[tex]\[
\text{Cost per kg} = \frac{\text{Total cost}}{\text{Weight in kg}} = \frac{960 \text{ Rs}}{8 \text{ kg}}
\][/tex]
[tex]\[
\text{Cost per kg} = 120 \text{ Rs/kg}
\][/tex]
So, the rate of cost of the grapes is Rs 120 per kg.
### Part (ii):
Now that we know the cost per kg of grapes, we can find the cost of 10 kg of grapes.
To find the total cost for 10 kg, we multiply the cost per kg by the weight in kilograms.
[tex]\[
\text{Cost of 10 kg} = \text{Cost per kg} \times \text{Weight in kg} = 120 \text{ Rs/kg} \times 10 \text{ kg}
\][/tex]
[tex]\[
\text{Cost of 10 kg} = 1200 \text{ Rs}
\][/tex]
So, the cost of 10 kg of grapes is Rs 1200.
