Answer :

520miles/ 1.3 hours = x miles/ 1 hour. 520(1) divided by 1.3 = 400mph

The speed of the airplane is 400 miles per hour.

What is the formula of speed ?

The formula of speed is, [tex]v=\frac{s}{t}[/tex]

where v is the speed, s is the travelled distance and t is the time interval in which the distance travelled.

What is the required speed ?

Given that, the airplane travels 520 miles in 1.3 hours.

So, Distance(s) = 520 miles & Time(t) = 1.3 hours

Speed, [tex]v=\frac{s}{t}[/tex]

             ⇒ v = [tex]\frac{520}{1.3}[/tex] = 400

So, Speed = 400 miles/hour

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