Discussion
Home ‣ Aptitude ‣ Average Comments
- Question
A pupil's marks were wrongly entered as 83 instead of 63. Due to that the average marks for the class got increased by half (1/2). The number of pupils in the class is:
Options- A. 10
- B. 20
- C. 40
- D. 73
- Correct Answer
- 40
Explanation
Let there be x pupils in the class.Total increase in marks = ❨ x x 1 ❩ = x 2 2 ∴ x = (83 - 63) ⟹ x = 20 ⟹ x= 40. 2 2 - 1. The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is:
Options- A. 35 years
- B. 40 years
- C. 50 years
- D. None of these Discuss
- 2. The average weight of 8 person's increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg. What might be the weight of the new person?
Options- A. 76 kg
- B. 76.5 kg
- C. 85 kg
- D. Data inadequate
- E. None of these Discuss
- 3. A library has an average of 510 visitors on Sundays and 240 on other days. The average number of visitors per day in a month of 30 days beginning with a Sunday is:
Options- A. 250
- B. 276
- C. 280
- D. 285 Discuss
- 4. The average weight of 16 boys in a class is 50.25 kg and that of the remaining 8 boys is 45.15 kg. Find the average weights of all the boys in the class.
Options- A. 47.55 kg
- B. 48 kg
- C. 48.55 kg
- D. 49.25 kg Discuss
- 5. A car owner buys petrol at Rs.7.50, Rs. 8 and Rs. 8.50 per litre for three successive years. What approximately is the average cost per litre of petrol if he spends Rs. 4000 each year?
Options- A. Rs. 7.98
- B. Rs. 8
- C. Rs. 8.50
- D. Rs. 9 Discuss
- 6. A cistern 6m long and 4 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:
Options- A. 49 m2
- B. 50 m2
- C. 53.5 m2
- D. 55 m2 Discuss
- 7. A boat having a length 3 m and breadth 2 m is floating on a lake. The boat sinks by 1 cm when a man gets on it. The mass of the man is:
Options- A. 12 kg
- B. 60 kg
- C. 72 kg
- D. 96 kg Discuss
- 8. How many bricks, each measuring 25 cm x 11.25 cm x 6 cm, will be needed to build a wall of 8 m x 6 m x 22.5 cm?
Options- A. 5600
- B. 6000
- C. 6400
- D. 7200 Discuss
- 9. A right triangle with sides 3 cm, 4 cm and 5 cm is rotated the side of 3 cm to form a cone. The volume of the cone so formed is:
Options- A. 12Π cm3
- B. 15Π cm3
- C. 16Π cm3
- D. 20Π cm3 Discuss
- 10. The curved surface area of a cylindrical pillar is 264 m2 and its volume is 924 m3. Find the ratio of its diameter to its height.
Options- A. 3 : 7
- B. 7 : 3
- C. 6 : 7
- D. 7 : 6 Discuss
Average problems
Search Results
Correct Answer: 40 years
Explanation:
Sum of the present ages of husband, wife and child = (27 x 3 + 3 x 3) years = 90 years.
Sum of the present ages of wife and child = (20 x 2 + 5 x 2) years = 50 years.
∴ Husband's present age = (90 - 50) years = 40 years.
Correct Answer: 85 kg
Explanation:
Total weight increased = (8 x 2.5) kg = 20 kg.
Weight of new person = (65 + 20) kg = 85 kg.
Correct Answer: 285
Explanation:
Since the month begins with a Sunday, to there will be five Sundays in the month.
| Required average |
|
|||||
|
||||||
| = 285 |
Correct Answer: 48.55 kg
Explanation:
| Required average |
|
|||||
|
||||||
|
||||||
| = 48.55 |
Correct Answer: Rs. 7.98
Explanation:
| Total quantity of petrol consumed in 3 years |
|
||||||||||||
|
|||||||||||||
|
Total amount spent = Rs. (3 x 4000) = Rs. 12000.
| ∴ Average cost = Rs. | ❨ | 12000 x 51 | ❩ | = Rs. | 6120 | = Rs. 7.98 |
| 76700 | 767 |
Correct Answer: 49 m2
Explanation:
| Area of the wet surface | = [2(lb + bh + lh) - lb] |
| = 2(bh + lh) + lb | |
| = [2 (4 x 1.25 + 6 x 1.25) + 6 x 4] m2 | |
| = 49 m2. |
Correct Answer: 60 kg
Explanation:
| Volume of water displaced | = (3 x 2 x 0.01) m3 |
| = 0.06 m3. |
| ∴ Mass of man | = Volume of water displaced x Density of water |
| = (0.06 x 1000) kg | |
| = 60 kg. |
Correct Answer: 6400
Explanation:
| Number of bricks = | Volume of the wall | = | ❨ | 800 x 600 x 22.5 | ❩ | = 6400. |
| Volume of 1 brick | 25 x 11.25 x 6 |
Correct Answer: 12Π cm3
Explanation:
Clearly, we have r = 3 cm and h = 4 cm.
| ∴ Volume = | 1 | Πr2h = | ❨ | 1 | x Π x 32 x 4 | ❩cm3 | = 12Π cm3. |
| 3 | 3 |
Correct Answer: 7 : 3
Explanation:
| Πr2h | = | 924 | ⟹ r = | ❨ | 924 | x 2 | ❩ | = 7 m. |
| 2Πrh | 264 | 264 |
| And, 2Πrh = 264 ⟹ h = | ❨ | 264 x | 7 | x | 1 | x | 1 | ❩ | = 6m. |
| 22 | 2 | 7 |
| ∴ Required ratio = | 2r | = | 14 | = 7 : 3. |
| h | 6 |
Comments
There are no comments.More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.