1. A racing driver drove around a 6-mile track at 140 miles per hour for 3 miles, 168 miles per hour for 1.5 miles, and 210 miles per hour for 1.5 miles. What was his average speed for the entire 6 miles?
2. A girl is twice as old as her brother and half as old as her father. In 22 years, her brother will be half as old as his father. How old is the daughter now?
The Big Book of Brain Games: 1,000 PlayThinks of Art, Mathematics & Science