AQA Large Data Set Practice Test

Counting distinct makes in a dataset. To answer how many car makes are included, you look at the make field and list each unique make that appears, counting each one only once. The correct result is five, meaning there are five different makes represented across all records. Remember that a single make can have many models, so you’re not counting every row, just the distinct makes. If some entries are missing a make, those don’t contribute to the count. So the database contains five unique car makes.