If an adult blinks 450 times in 30 minutes, then he will blink 900 times in 60 minutes.
A 12-year old blinks 150 times in 15 minutes, so he will blink (150 x 4) in 60 minutes, which comes out to: 600.
so 900-600
An adult blinks 300 times more in 60 minutes than a 12-year old.