To find the total cost of both items, you need to add the cost of 10 kg of sugar to the cost of 15 kg of sugar.
The cost of 10 kg of sugar is Rs. 1557, and the cost of 15 kg of sugar is Rs. 1278.
Adding these two costs together, we get:
1557 + 1278 = 2835
Therefore, the total cost of both items is Rs. 2835.
Rounding this value to two significant figures, we get Rs. 2800.