Average sums for all competitive exams

Here is the super solution for those who are worrying about the problematic sums on average!

Introduction

The average sums are takes place in all the competitive exams like TNPSC, SSC, and Bank exams, which also used in many interview questions. Here we have given the solved problems with formulas through which you can learn easily and crack your exams!

Formulas:

Average = Sum of observations / Number of observations

Average Speed:

Suppose a man covers a certain distance at x kmph and an equal distance at y kmph. Then, the average speed during the whole journey is (2xy / x + y) kmph.

1. There are 459 students in a hostel. If the number of students increased by 36, the expenses of the mess increased by Rs.81 Per day while the average expenditure per head reduced by 1. Find the original expenditure of the mess?

Answer: Rs. 7344.

Explanation:

Let x be the expenditure of one person Total expenditure = 459x

Total number of students = 459 + 36 = 495

36 students joined then total expenditure = 459x + 81 Average expenditure per head reduced by 1 Average = (459x + 81) / 495 (459x + 81) / 495 = x-1 459x + 81 = 495x - 495

495 + 81 = 495x - 459x

36x = 576

x = 16

Original expenditure = (16 * 459) = Rs. 7344

Original expenditure is Rs. 7344

2. The average price of 80 mobile phones is Rs.30,000. If the highest and lowest price mobile phones are sold out then the average price of remaining 78 mobile phones is Rs. 29,500. The cost of the highest mobile is Rs.80,000. The cost of lowest price mobile is?

Answer: Rs. 19000

Explanation:

The average price of 80 mobile phones = Rs.30,000 The average price of 78 mobile phones = Rs. 29,500 The price of the costliest and cheapest mobile

= (80 * 30000) - (78 * 29500)

= 2400000 - 2301000 = 99000

Cheapest Mobile Price = 99000 - 80000

= 19000

The cost of lowest price mobile is Rs. 19000

3. The average expenditure of Sharma for the January to June is Rs. 4200 and he spent Rs. 1200 in January and Rs.1500 in July. The average expenditure for the months of February to July is:

Answer: Rs. 4250.

Explanation:

Total Expenditure (Jan - June) is

= 4200 * 6

= 25200

Total Expenditure (Feb - June) is

= 25200 - 1200

= 24000

Total Expenditure (Feb - July) is

= 24000 + 1500

Average Expenditure (Feb - July) is

= (25500 / 6) = 4250

The average expenditure is Rs. 4250.

4. The average weight of all the 11 players of Team is 50 kg. If the average of first six lightest weight players of Team is 49 kg and that of the six heaviest players of Team is 52 kg. The average weight of the player which lies in the sixth position in the list of players when all the 11 players of Team are arranged in the order of increasing or decreasing weights.

Answer: 56kg.

Explanation:

Average weight of First six players is

= 49 * 6

= 294

Average weight of Last six players is

= 52 * 6

= 312

Average weight of all players is

= 50 * 11

= 550

Average weight of sixth player is

= 294 + 312 - 550

= 56

The average weight is 56kg.

5. 3 years ago, the average of a family of 5 members was 18 years. A baby having been born; the average age of the family is the same today. The present age of the baby is?

Answer: 3 years

Explanation:

Given data,

Total age of 5 members, 3years ago = 18 * 5

= 90 years

Total age of 5 members now = 90 + (3 * 5)

= 90 + 15

= 105 years

Total age of 6 members now = (18 * 6)

= 108 years

Age of the baby = 108 - 105

= 3 years

Age of the baby = 3 years.

Conclusion

Are you a fresher? Struggling with where to get a job? Nithra Jobs is the best place to get all kinds of jobs that are available on our site. It was the best site to get all kinds of local jobs in Tamil Nadu.