BANK & INSURANCE (AVERAGE) PART 1

Total Questions: 45

11. Average weight of 42 students is 54kg. A new student comes and the average weight of the whole class increases by 1kg. What is the weight of the new student?

Correct Answer: (e) 97
Solution:Total weight of 42 students is=54 × 42=2268
Total weight of 43 students is=55 × 43=2365
So weight of new student is=2365-2268=97

12. The average earning of a mechanic for the first four days of a week is Rs.18 and for the last four days is Rs.22. If he earns Rs 20 on the Fourth day, his average earning for the whole week is?

Correct Answer: (a) 20  
Solution:Total earning first four days=18 × 4=72
Total earning in last four days=22 × 4=88
Earning on fourth day=20
Total earn in 7 days is=72+88-20=140
So average earning in five days is=140/7=20

13. A person goes to a certain place at the speed of 4 kmph. He returns on bicycle at the speed of 16 kmph. Find his average speed during the whole journey

Correct Answer: (c) 6.4
Solution:Let the distance is D km So he goes with speed in 4kmph
So time taken D/4 hr He come back with speed 16kmph
So time taken=D/16 hr
Average speed = total distance/ total time
= [2D/(D/4+D/16)] = 6.4kmph

14. The average marks of 50 students in a class is 78. The average marks of boys and girls is 77 and 79 respectively. Then find the number of boys in the class?

Correct Answer: (b) 25  
Solution:Total marks of 50 students is=78 × 50=3900
Let boys is x and girls is 50-x
77x+79(50-x)=3900
Or,-2x=-50 or, x=25
Number of boys is 25.

15. In a joint family the average age of grandparents is 67 years, the average age of parents is 35 years and age of grandchildren is 6 years. What is the average age of the family?

Correct Answer: (a) 42  
Solution:Total age of grandparents is=67 × 2=134
Total age of parents=35 × 2=70
Total age of five members is=134+70+6=210
Average age is=210/5=42

16. The average age of a class of 15 boys is 11 years. If 5 new boys having an average age of 9 years join the class, then the average age of the class becomes?

Correct Answer: (e) 10.5
Solution:Total age of 15 boys is=15 × 11=165
Total age of 20 boys is=165+5 × 9=165+45=210
So new average=210/20=10.5

17. If the average temperature of the first four days of week was 39°C and the average temperature of the week was 40°C, then what was the average temperature of the last three days of the week?

Correct Answer: (d) 41.33  
Solution:Total temperature of first four days=39 × 4=156
Total temperature of the week is=40 × 7=280
Total temperature of last three days=280-156=124
Average temperature of last three days=124/3=41.33

18. The average temperature of the first three days is 27°C and that of the next three days is 29°C. If the average of the entire week is 28.5°C, then the temperature of the last day is?

Correct Answer: (c) 31.5
Solution:Total temperature of first three days=27 × 3=81
Total temperature of next three days=29 × 3=87
Total temperature of the week is=28.5 × 7=199.5
Last day temperature is=199.5-81-87=31.5

19. The average of 30 results is 20 and that of other 20 results is 30. What is the average of all the results?

Correct Answer: (b) 24  
Solution:Total sum of 30 results is=30 × 20=600
Total sum of 20 results is=20 × 30=600
Total sum of 50 results is=600+600=1200
So average of 50 result is=1200/50=24

20. If the average of 12, 13, 14.5, 16.8, X, 11.5 is 13.4. Then find the value of X?

Correct Answer: (a) 12.6  
Solution:Sum of the number of series,
12+13+14.5+16.8+X+11.5=13.4 × 6=80.4
67.8+X=80.4
X=80.4-67.8=12.6