The sum of ages of 4 children born at intervals of 4 years each is 60. What is the age of the youngest child?

Options

A. 7
B. 9
C. 10
D. 12

Explanation

To solve the problem step by step, we can follow these instructions:

### Step 1: Define the variables
Let the age of the youngest child be \( x \).

### Step 2: Determine the ages of the other children
Since the children are born at intervals of 4 years, we can express the ages of the other children as:
- Age of the second child: \( x + 4 \)
- Age of the third child: \( x + 8 \)
- Age of the fourth child: \( x + 12 \)

### Step 3: Write the equation for the sum of their ages
According to the problem, the sum of their ages is 60. Therefore, we can write the equation:
\[ x + (x + 4) + (x + 8) + (x + 12) = 60 \]

### Step 4: Simplify the equation
Combine like terms:
\[ x + x + 4 + x + 8 + x + 12 = 60 \]
This simplifies to:
\[ 4x + 24 = 60 \]

### Step 5: Solve for \( x \)
Subtract 24 from both sides:
\[ 4x = 60 - 24 \]
\[ 4x = 36 \]
Now, divide both sides by 4:
\[ x = \frac{36}{4} \]
\[ x = 9 \]

### Step 6: Conclusion
The age of the youngest child is \( 9 \) years.

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