I want to know the answer to the following question:
What was the average speed of a winning solar powered car in 1987?
All the background I'm provided with is that "In 1987, when it was founded, the winner's average speed was 67 kilometres per hour (42 mph) and by 2007 the winner's average speed had improved to 90.87 kilometres per hour (56.46 mph).". Is that enough to answer the question?