AMCAT Averages Quiz-3

Explanation :
Average monthly expenditure for 3 months
= Rs. 2750
Total expenditure for 3 months = Rs 2750 \times 3 = Rs. 8250
Average monthly expenditure for 3 months
= Rs. 2940
Total expenditure for 3 months = Rs 2940 \times 3 = Rs. 8820
Average monthly expenditure for 3 months
= Rs. 3150
Total expenditure for 3 months = Rs 3150 \times 3 = Rs. 9450
Total savings for 9 months = 4980
Average monthly income for 9 months = \frac{(8250 + 8820 + 9450 + 4980)}{9}
= 3500

Explanation:
Total present age of the family (8*24) = 192 years
Total age of the family 6 years ago = (192 –6*7) = 150 years
At that time, Total members in the family = 7
Therefore Average age at that time = 150/7
= 21.42 years

Explanation:
Let number of females be x.
Average Monthly Consumption of Rice by all 10 males = 10 x 10
Average Monthly Consumption of Rice by all x no. of females = x x 6
Total Number of family members = 10 + x
\frac{(10*10+x*6)}{(10+x)} = 8
x = 10

Explanation:
Total number of rooms = 29
So, total earnings per room for the first half of September = 15 * 5000 = Rs. 75,000
So, total earnings per room for the latter half of September = 15 * 3000 = Rs. 45,000
Therefore, total earnings per room for the entire month of September = Rs. 75,000 + Rs. 45,000 = Rs. 1,20,000
Now, Number of Rooms = 30
Total earnings for all rooms for September = 30 x 120000 = Rs 3600000
Since, Number of days in September = 30
Average income per room per day over the month,
= (Total earnings for all rooms for 30 Days) / (30 x No. of rooms)
= (36,00,000) / (30 x 30)
= Rs 4000

Explanation:
Total number of rooms in first, second and third floor = 30, 20, 30
Occupied rooms in first, second and third floor = 15, 16, 12
Average income = \frac{(15 * 200 + 16 * 250 + 12 * 300)}{80}
= Rs. 132.5

Explanation:
Total students=46+8=54
Let expenditure per student be x
So expenditure after 8 new students = x-1
54*(x−1)−46*x = 42
8x = 96
x = 12
Original total expenditure:
46*x = 46*12 = Rs.552

Explanation:
Let the required number of non–officers = x
200x + 520*15 = 250 ( 15 + x )
250x – 200x = 520 * 15 – 250 * 15
50x = 4050
x = 81

Explanation:
Anil kapoor’s average monthly expenditure for the first four months of the year = Rs.260.
260 * 4 = Rs. 1040
For the next five months,the average monthly expenditure was Rs.40 more than
what it was during the first four months. He spent 260 + 40 for one month
In 5 months he spent 300 * 5 = 1500
He spent Rs.560 in all during the remaining three months of the year.
Total expenditure = 1040 + 1500 + 560 = 3100
Savings = 5000-3100 = 1900
% savings = 1900/5000 * 100 = 38%

Explanation:
Initial number of persons = x
22x + 25 * 10 = 12(x + 25)
10x = 50
x = 5

Explanation:
Total deduction in average marks of 100 candidates=(74 – 54) * 100
(74 – 54) * 100 = 25 * x
x = 20 * 100 / 25 = 80