# Quantitative Aptitude: Average Questions Set 7

1. The average salary of all the employees in an office is Rs. 10000. The average salary of 8 Management head is Rs. 15000 and the average salary of the rest is Rs. 6000. The total number of employees in the office is
14
18
12
15
None
Option B
Solution:
15000——–6000
——10000——–
4000———5000
Ratio 4:5.
4—-8
9—-? ==> 18.
2. A number, x equals 80% of the average of 5, 7, 14 and a number y. If the average of x and y is 26, then value of y is
42
35
26
39
None
Option D
Solution:
Average of 5,7,14 and y =(5+7+14+y) /4
Then x=80% of (5+7+14+y) /4
=80/100 *(26+y)/4
x=(26+y)/5
And (x+y)/2=26
Equating both 52-y=(26+y)/5
260-5y=26+y
y=39.
3. On an average 150 people visited the church on Monday, Wednesday and Thursday and the average number of visitors on Tuesday and Friday is 250. If the average number of visitors per day in the week be 350, then the average number of people who visited the church in weekends is
500
550
750
600
None
Option C
Solution:
Average of Mon + Wed + Thus=150*3 = 450
Average of Tues +Fri =250*2 = 500
Average of Mon to sun=350*7 = 2450
Then Average on weekends =1/2 [2450 – (450+500)] =1/2*(1500)
=750.
4. Out of ten persons, 9 persons spent Rs. 30 each for their lunch. The tenth one spent Rs. 90 more than the average expenditure of all the ten. The total money spent by all of them was
Rs400
Rs360
Rs420
Rs380
None
Option A
Solution:
Let the average be x.
Then 10x =9*30 + (x+60)
10x=270+60+x
9x=360
x=40.
Total money spent= 10*40 =Rs400.
5. The average of first three numbers is five times of the fourth number. If the average of all the four numbers is 20. Find the 4th number.
8
5
10
6
None
Option B
Solution:
Let the four numbers be w, x, y, z
(w+x+y+z) / 4=20
w+x+y+z = 80
(w+x+y)/3=5z
w+x+y= 15z
then 15z+z=80
16z=80
z=5.
6. There were 45 girls in a women hostel. Due to the admission of 15 new girls, the expenses of the mess increases by Rs30 per day while the average expenditure per head diminished by Rs3. What was the original expenditure of the mess?
Rs560
Rs600
Rs520
Rs630
None
Option D
Solution:
Let the expenses per girl be x.
Then 60(x-3) – 45x = 30
60x- 180 – 45x =30
15x=210
x=14.
The original expenditure be 45*14=Rs630.
7. The average of three numbers is 32. The largest number is 40 and the difference between the other two is 4. The smallest number is
24
26
30
35
None
Option B
Solution:
Let the three numbers be a ,b and c.
a + b + c = 32*3 =96
b + c = 96 – 40
b+c=56
b-c = 4
Solving both we get
2b = 60
b = 30
then c = 26.
8. The average of 7 consecutive numbers is 17. The largest of these numbers is
22
19
20
18
None
Option C
Solution:
Let the numbers be x-3, x-2, x-1, x, x+1, x+2, x+3.
[(x-3) + (x-2) + (x-1) + x+ (x+1) +(x+2) + (x+3)]/7 =17
7x/7 =17
x=17.
Largest no =x+3=17+3=20.
9. 5 years ago, the average age of P, Q and R was 25 year; 7 years ago the average age of Q & R was 20 years. Find the present age of P?
36yrs
32yrs
28yrs
27yrs
None
Option A
Solution:
Present age of P+Q+R = 25*3+ 5*3= 90
Present age of Q+R= 20*2 + 7 *2 = 54
Present age of P = 90-54 = 36yrs.
10. The average rain fall in the months of January and February is 8 cm and in the months of March to June is 5 cm and July to October is 10 cm and in the November and December, it is 7 cm. The average rainfall for the whole year is
7 cm
7.5 cm
6cm
6.5cm
None
Option B
Solution:
Jan + Feb = 8*2 = 16
Mar to Jun = 5*4 = 20
Jul to Oct = 10*4 = 40
Nov + Dec = 7*2 = 14
Average = (16+20+40+14)/12 = 7.5 cm.