Answer :

Certainly! Let's solve this step-by-step.

### Step 1: Understand the Problem
We need to find how many men, each having an average mass of 77 kg, together have a total mass of 1 tonne.

### Step 2: Convert Tonne to Kilograms
1 tonne is equal to 1000 kilograms. Therefore, the total mass we are considering is 1000 kg.

### Step 3: Set Up the Equation
We need to find the number of men \( n \) such that their combined mass is 1000 kg. Since each man has an average mass of 77 kg, the equation becomes:

[tex]\[ 77 \times n = 1000 \][/tex]

### Step 4: Solve for \( n \)
To find \( n \):

[tex]\[ n = \frac{1000}{77} \][/tex]

### Step 5: Perform the Division
When we divide 1000 by 77, we get:

[tex]\[ n \approx 12.987012987012987 \][/tex]

### Step 6: Interpretation
Thus, approximately 12.99 men are needed to collectively have a mass of 1 tonne.

### Conclusion
Approximately 13 men (since you can't have a fraction of a person in practical terms) are required to have a combined mass of 1 tonne.