Find the speed of the jet in still air and the speed of the wind.

Question

A passenger jet can fly 1,290 miles in 3 hours with a taiwind but only 1,230 miles in 3 hours into a headwind. 

Answer 1

Hi Ashlyn, let w represent the wind's speed and v represent the plane's speed. Use the equation, distance = rate times time to solve.

 

Equation with the wind:

 

1290 = (v + w) * 3

 

Equation against the wind:

 

1230 = (v - w) * 3

 

This gives us two equation, which can be solved using elimination.

 

1290 = (v + w) * 3

1230 = (v - w) * 3

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Divide both sides by 3:

 

430 = v + w

410 = v - w

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Add the two equation getting:

 

840 = 2v

 

Solve for v:

 

v = 420

 

Solve for w by replacing v in one of the two equations:

 

1290 = (420 + w) * 3

 

1290 = 1260 + 3w

 

Combine terms:

 

3w = 30

 

w = 10

 

The speed of the plane is 420 miles per hour and the speed of the wind is 10 miles per hour.

 

Questions?