Safety regulations require that the time between airplane takeoffs (on the same runway) will be at least 2 minutes. When taking off, the run time of an airplane on the runway is 36 seconds. Planes are on average waiting 3 minutes and 30 seconds for take-off. On average there are 18 planes taking off per hour. How many planes are either on the runway or waiting to take off

1 plane

Step-by-step explanation:

Let's suppose the number of planes waiting or on the runway " P "

the number of planes taking off per hour ' '

the time for waiting and the runway so:

P =   x

= 18 airplanes per hour

we know that 1 min = 60s

36s = 36/60 = 0.6 min

Also, 3 min and 30 s = 3 + 30/60 = 3.5 min

Next to find the time for waiting and the runway

∴= 0.6 + 3.5  = 4.1 min/60 (converting into hour)

= 0.068 hour

P = 18x0.068 = 1.23

therefore, there is 1 plane either on the runway or waiting to take off

So, there is 1 plane either on the runway or waiting to take off

Read more on -

a = 11 : 4

b = 38

c = 1 for every 6

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this