Answer:
-28%
Step-by-step explanation:
Let the number of chickens = c.
Let the number of pigs = p.
A chicken has 1 head and 2 legs.
c number of chickens have c heads and 2c legs.
A pig has 1 head and 4 legs.
p number of pigs have p heads and 4p legs.
There are 40 heads.
Equation for heads:
c + p = 40
There are 110 legs.
Equation for legs:
2c + 4p = 110
System of equations:
c + p = 40
2c + 4p = 110
Solve the first equation of the system of equations for c:
c = 40 - p
Substitute 40 - p for c in the second equation:
2c + 4p = 110
2(40 - p) + 4p = 110
80 - 2p + 4p = 110
80 + 2p = 110
2p = 30
p = 15
Now substitute p = 15 in the first equation to find c.
c + p = 40
c + 15 = 40
c = 25
There are 25 chickens and 15 pigs.
The diameter of a circle passes through the middle
Answer:
2.35%
Step-by-step explanation:
Mean number of months (M) = 39 months
Standard deviation (S) = 10 months
According to the 68-95-99.7 rule, 95% of the data is comprised within two standard deviations of the mean (39-20 to 39+20 months), while 99.7% of the data is comprised within two standard deviations of the mean (39-30 to 39+30 months).
Therefore, the percentage of cars still in service from 59 to 69 months is:

The approximate percentage of cars that remain in service between 59 and 69 months is 2.35%.