Mr. Sohanlal is 4 times as old as his son.Four years hence the sum of their ages will be 43 years. The present age of son is-

Options

A. 5 years
B. 7 years
C. 8 years
D. 10 years

Answer

To solve the problem, we will follow these steps:

### Step 1: Define Variables
Let the present age of the son be \( x \) years. Since Mr. Sohanlal is 4 times as old as his son, his present age will be \( 4x \) years.

### Step 2: Set Up the Equation for Future Ages
In 4 years, the son's age will be \( x + 4 \) and Mr. Sohanlal's age will be \( 4x + 4 \). According to the problem, the sum of their ages in 4 years will be 43 years. Therefore, we can write the equation:
\[ (x + 4) + (4x + 4) = 43 \]

### Step 3: Simplify the Equation
Now, simplify the equation:
\[ x + 4 + 4x + 4 = 43 \]
Combine like terms:
\[ 5x + 8 = 43 \]

### Step 4: Solve for \( x \)
Next, we will isolate \( x \):
\[ 5x = 43 - 8 \]
\[ 5x = 35 \]
\[ x = \frac{35}{5} \]
\[ x = 7 \]

### Step 5: Conclusion
The present age of the son is \( 7 \) years.