Question

the average expenditure of a man for first 7 months is rupees 800 and for next 5 months is 900 find the average of monthly expenditure

Answer 1

800×7+900×5/12=841.66

Answer 2

average monthly expenditure = total expenditure / no. of months

total expenditure=7×800 +5×900=5600+4500=10100
no. of months=7+5=12

so, avg. =10100/12=841.66

thanks.