Answer:
a. 90
b. 360
Step-by-step explanation:
The time taken by humming bird to flap its wings= 0.08 sec
by flying 7.2 seconds a typical giant hummingbird flap its wings times
= 90 times
Since, A ruby-throated hummingbird can flap its wings 4 times faster than a giant hummingbird, it will flap its wings in every 0.02 sec
so in 7.2 seconds it will flap times = 360 times