Formula Used:
Income
= Expenditure
+ Savings
Average
=( Sum of the terms
)∕ Number of the terms
)Calculation:
According to the question,
Average monthly expenditure for the first 3 months
= Rs. 4,000
Total expenditure for the first 3 months
=4,000×3= Rs. 12,000
Average monthly expenditure for the next 4 months
= Rs. 4,500
Total expenditure for the next 4 months
=4,500×4= Rs. 18,000
Average monthly expenditure for the next 5 months
= Rs. 5,000
Total expenditure for the next 5 months
=5,000×5= Rs. 25,000
Total expenditure during the year
=12,000+18,000+25,000⇒55,000Given, total saving during the year
= Rs. 5,000
We know that, Income
= Expenditure
+ Savings
Income during the year
=55,000+5,000= Rs. 60,000
Average monthly income = Income during the year/Number of months in a year
Average monthly income
== Rs. 5,000