There's a relatively easy way to solve problems of this nature. You determine the contribution made if the only contributor is the one that contributes the least.
A chicken has the least number of feet, so 24 chickens will contribute 48 feet.
Now, you consider the change in contribution made by substituting a larger contributor. Each pig that replaces a chicken will add 2 feet to the total.
Consider how many feet need to be added, and thus how many larger contributors are needed. 80 -48 = 32 feet need to be added, so 32/2 = 16 of the animals need to be pigs.
There are 16 pigs and 8 chickens.
Answer: the speed of the plane is 130 mph
Step-by-step explanation:
Let x represent the speed of the plane. If the car travels 80 mph slower than the plane, then the speed of the car would be (x - 80) mph.
Time = Distance/speed
plane can fly 520 miles in the same time as it takes a car to go 200 miles. This means that the time it takes the plane to fly 520 miles is
520/x
Also, the time it takes the car to drive 200 miles is
200/(x - 80)
Since the time is the same, it means that
520/x = 200/(x - 80)
Cross multiplying, it becomes
520(x - 80) = 200 × x
520x - 41600 = 200x
520x - 200x = 41600
320x = 41600
x = 41600/320
x = 130 mph
Answer: 0.7 i believe not sure
Step-by-step explanation:
The correct answer is B, C and E