To answer this question, we can state the problem as follows:
1. The two planes are 1180 miles apart.
2. They fly toward each other.
3. Their speed differs by 40 mph: that is one of the planes is faster than the other 40 mph, or the other plane is slower than the other plane.
4. The time they encounter each other is 2 hours.
Then, we need to remember the formula for a constant speed:
Where
• d is the distance
,
• t is the time
Then, we have that the speeds for each of the planes are:
We also have that the sum of the distance for both planes is 1180 miles:
And we have that:
But
Then, we have that:
Since t = 2, we have:
Subtracting 80 from both sides of the equation:
Dividing both sides of the equation by 4, we have:
Since we know that:
Then, we have:
In summary, therefore, the speed of each plane is:
• Speed of Plane 1 = 315 mph
,
• Speed of Plane 2 = 275 mph