Question

If the average income of seven families is Rs. 4200 and a family with an income of Rs. 1000 joins them, then the average income of all eight families is (in Rs)

• A. 3800
• B. 3700
• C. 3600
• D. 3900

Answer 1

The Correct Option is A

The total income of the seven families is:
\[ \text{Total Income of 7 families} = 4200 \times 7 = 29400 \]
The new total income with the additional family is:
\[ \text{New Total Income} = 29400 + 1000 = 30400 \]
The average income of all eight families is:
\[ \text{Average Income} = \frac{30400}{8} = 3800 \]

To find the new average, add the new value to the total and divide by the new number of items.