A dealer purchased 250 bulbs for Rs10 each. However, 12 bulbs got fused which he had to throw away. He sold the remaining bulbs at Rs 12 each. Find the gain or loss per cent in the dealing.​

At the beginning of a call to the cable company, a message tells customers, "after you finish talking to our customer service representative, you will be asked to take a five-question survey about the level of service you recieved. it would be appreciated if you could stay on the line to answer the survey questions." what type of sampling is the cable company using?