{"blocks": [{"key": "2d283b21", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "3e18bd6d", "text": "Design an object-oriented Delivery Cost System that supports:", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "75330ff2", "text": "Driver registration (each driver has an hourly rate).", "type": "unordered-list-item", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "2f59db69", "text": "Recording a delivery (driver ID, start time, end time).", "type": "unordered-list-item", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "d2e1c82c", "text": "getTotalCost() – return total cost of all recorded deliveries.", "type": "unordered-list-item", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "a25108b4", "text": "payUpTo(timestamp) – mark all deliveries ending on or before the given timestamp as paid.", "type": "unordered-list-item", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "a7280527", "text": "getTotalUnpaid() – return total unpaid cost.", "type": "unordered-list-item", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "f30d51a9", "text": "maxSimultaneousDriverInPast24Hours() – return the maximum number of drivers that were simultaneously on a delivery within the past 24 hours.", "type": "unordered-list-item", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}