Question Details

The population of a village is 11000. If the number of children increase by 11% and the number of adults increase by 20%, the population becomes 12660. Find the population of children and adults separately in the village.

Options

A

7000, 4000

B

4500, 6500

C

6000, 5000

D

5500, 5500

Correct Answer :

6000, 5000

Solution :

The correct option is 6000, 5000.

To find the population of children and adults separately, we can set up a system of linear equations based on the given information.

Step 1: Define the variables
Let the initial number of children in the village be C and the initial number of adults be A.

Step 2: Formulate the equations
According to the problem, the total initial population of the village is 11,000. This gives us our first equation:

C+A=11000

Next, we are told that the number of children increases by 11% and the number of adults increases by 20%, making the new population 12,660. We can write the expression for the increase in population:
The increase in children is 11% of C, which is 0.11C.
The increase in adults is 20% of A, which is 0.20A.

The total increase in population is the difference between the new population and the initial population:

12660-11000=1660

This gives us our second equation:

0.11C+0.20A=1660

Step 3: Solve the system of equations
From the first equation, we can express A in terms of C:

A=11000-C

Now, substitute this expression for A into the second equation:

0.11C+0.20(11000-C)=1660

Expand the equation:

0.11C+2200-0.20C=1660

Combine the terms containing C:

-0.09C+2200=1660

Subtract 2200 from both sides of the equation:

-0.09C=1660-2200

-0.09C=-540

Divide by -0.09 to find C:

C=-540-0.09

C=6000

Step 4: Find the population of adults
Substitute the value of C back into the expression for A:

A=11000-6000

A=5000

Therefore, the population of children is 6,000 and the population of adults is 5,000 in the village.

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