Answer:
680,000
Step-by-step explanation:
Population before growing rate: 400,000
Growing rate: 7%
Duration: 10 years
___
First, you will have to calculate how much does the population increase each year with the said rate, so you will have to multiply the rate by the population to determine that amount.
400,000 x 7/100 = 28,000
So the population increases by 28,000 each year, now you will have to multiply that amount by the amount of years to determine how much the amount of increase.
28,000 x 10 = 280,000
This means that the population has increased by 280,000 in these 10 years. Finally, you will have to add that number to the population amount to get the answer.
400,000 + 280,000 = 680,000
Answer:
6.9
7.-5
8.-10
Step-by-step explanation:
Answer:
Step-by-step explanation:
∩
is asking for the intersection of sets
and
, or simply, which numbers can be found in both sets.
The numbers shared between the two sets are
.
Next, we need to union this result with the set
, or simply, combine the numbers in both sets together.
This would result in 
Answer: old McDonald has 54 chickens and 2 cows.
Step-by-step explanation:
Let x represent the number of chickens that old McDonald have.
Let y represent the number of cows that old McDonald have.
He counted 56 heads. A chicken and a cow has one head each. It means that
x + y = 56
He counted 116 legs. A chicken has 2 legs and a cow has 4 legs. It means that
2x + 4y = 116 - - - - - - - - -1
Substituting x = 56 - y into equation 1, it becomes
2(56 - y) + 4y = 116
112 - 2y + 4y = 116
- 2y + 4y = 116 - 112
2y = 4
y = 4/2 = 2
x = 56 - y = 56 - 2
x = 54