Part A: A mockingbird beats its wings 420 times per 30 seconds (half a minute). This means that a mockingbird will beat its wings 840 times per minute. Multiply this by two and you get 1680 times in two minutes.
Part B: Divide the amount of beats in a minute by 60 (because there are 60 seconds in a minute) and you get the amount of times a mockingbird beats it wings per second.
420/30 = 14 times per second
Ariel said it was 0.07 times per second which is incorrect.
