Answer:
300
Explanation:
An adult blinks
450 in 30 minutes
900 in 60 minutes (multiply 2 on both sidds)
A 12-year-old blinks
150 times in 15 minutes
600 times in 60 minutes (multiply 4 on both sides)
Difference:
900 - 600 = 300.
An adult blinks 300 more times.