The first bird can fly about 20 mph faster than the second one. In the same time that the first bird travels 120 miles, the second bird travels 60 miles. Find their flying speeds.
A)The first bird: 41 mph; the second bird: 21 mph
B)The first bird: 37 mph; the second bird: 17 mph
C)The first bird: 40 mph; the second bird: 20 mph
D)The first bird: 42 mph; the second bird: 22 mph
E)The first bird: 36 mph; the second bird: 16 mph

Question

Quizplus · Accepted Answer

Let's call the speed of the second bird "x". According to the problem, the first bird can fly 20 mph faster, so its speed is "x+20". We know that they both fly for the same amount of time, and in that time, the first bird travels 120 miles and the second bird travels 60 miles. We can use the formula distance = rate x time to set up two equations:
120 = (x+20) x time
60 = x x time
We can solve for time in the second equation by dividing both sides by x:
time = 60/x
Now we can substitute that value for time into the first equation and solve for x:
120 = (x+20) x (60/x)
120 = 60 + 1200/x
60 = 1200/x
x = 20
So the speed of the second bird is 20 mph, and the speed of the first bird is x+20, or 40 mph. Therefore, the answer is choice C.

The First Bird Can Fly About 20 Mph Faster Than