The average weight of 4 men is increased by 3 kg when one of them who weighs 120 kg is replaced by another man. What is the weight of new man?

Options

A. 140 kg
B. 150 kg
C. 132 kg
D. 160 kg

Answer

To find the weight of the new man who replaces the man weighing 120 kg, we can follow these steps:

### Step 1: Understand the average weight increase
The average weight of the 4 men increases by 3 kg. This means that the total weight of the 4 men has increased by \(4 \times 3 = 12\) kg.

### Step 2: Calculate the total weight before the replacement
Let the total weight of the 4 men before the replacement be \(T\). Since one man weighing 120 kg is replaced, the total weight after the replacement can be expressed as:
\[ T - 120 + x \]
where \(x\) is the weight of the new man.

### Step 3: Set up the equation
According to the information given, the new total weight is equal to the old total weight plus the increase in weight:
\[ T - 120 + x = T + 12 \]

### Step 4: Simplify the equation
Now, we can simplify the equation:
\[ -120 + x = 12 \]
Adding 120 to both sides gives:
\[ x = 12 + 120 \]

### Step 5: Calculate the weight of the new man
Now, we can calculate \(x\):
\[ x = 132 \text{ kg} \]

Thus, the weight of the new man is **132 kg**.

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