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- Question
- Average age of 5 boys is 16 yr,of which that of 4 boys is 16 yr, 3 months. The age of the 5th boys.
Options- A. 15yr
- B. 15yr 6 months
- C. 15 yr 4 months
- D. 15 year 2 months
- Correct Answer
- 15yr
ExplanationAverage of 5 boys = 16 yr
sum of age of 5 boys = 16 x 5 = 80 yr
? Average age of 4 boys = 16 - yr 3 month
= 16 yr + 3/12 yr = 16 yr + 1/4 yr
Sum of ages of 4 boys = 4 x (16 +1/4) yr
= 64 +1 = 65 yr
? Age of 5th boy = (80 - 65) yr = 15 yr - 1. The average of 8 numbers is 14. The average of 6 of these numbers is 16. What is the average of the remaining two numbers?
Options- A. 12
- B. 6
- C. 8
- D. 10 Discuss
- 2. Calculate the average of the cubes of first five natural numbers.
Options- A. 55
- B. 65
- C. 45
- D. 35 Discuss
- 3. What will be the average of even numbers between 11 to 63.
Options- A. 37.5
- B. 47
- C. 42
- D. 37 Discuss
- 4. The average of A and B is 20 years. If C were to replace A, the average would be 19 and if C were to replace B, the Average would be 21. What are the ages of A, B and C?
Options- A. 22, 18, 20
- B. 18, 22, 20
- C. 20, 22, 18
- D. 18, 20, 22 Discuss
- 5. 5 years ago, the average of Ram and Shyam age was 20 years. now, the average age of Ram , Shyam and Mohan is 30 years . what will be Mohan's age 10 years hence?
Options- A. 45 years
- B. 50 years
- C. 49 years
- D. 60 years Discuss
- 6. Eight consecutive numbers are given. If the average of the two number that appear in the middle is 6 then the sum of the eight given numbers is
Options- A. 36
- B. 48
- C. 54
- D. 64 Discuss
- 7. The average of 4 consecutive even numbers is 27. What is the greatest number
Options- A. 28
- B. 26
- C. 32
- D. 30 Discuss
- 8. A businessman purchased 30 TV sets in ? 300000, If the average cost of 15 TV sets is ? 9000 then find out the average cost of remaining TV sets.
Options- A. ?20000
- B. ? 12000
- C. ? 11000
- D. ?10000 Discuss
- 9. The average age of 30 girls is 13 yr. The average of first 18 girls is 15 yr. Find out the average age of remaining 12 girls.
Options- A. 12yr
- B. 10yr
- C. 16yr
- D. 10.5 yr. Discuss
- 10. The average of four consecutive numbers A, B, C, and D is 49.5. What is the product of B and D?
Options- A. 2499
- B. 2352
- C. 2450
- D. 2550 Discuss
Average problems
Search Results
Correct Answer: 8
Explanation:
Average of 8 numbers = 14
Sum of 8 numbers = 14 x 8 = 112
Similarly, average of 6 numbers = 16
Sum of 6 number = 16 x 6 = 96
? Sum of remaining two number
= Sum of 8 number - sum of 6 numbers
= 112- 96 = 16
Average = (sum of two number)/2 = 16/2 = 8
Correct Answer: 45
Explanation:
As per the formula,
Average of the cubes os 1st 'n' natural numbers= n(n+1)2/4
where, n= 5.
? Required average = 5(5+1)2/4
= (5 x 36)/4 = 5 x 9= 45
Correct Answer: 37
Explanation:
Even numbers between 11 to 63
= 12,14,16,18,20,..........,62.
Clearly, this is a series of consecutive even number
According to the formula
Average of consecutive even numbers = (First number + Last number)/2
= (12 + 62)/2
= 74/2
= 37
Correct Answer: 20, 22, 18
Explanation:
Let a, b, c are the ages of A, B and C respectively
a + b = 2 X 20 = 40 ...(1)
b + c = 2 x 19 = 38 ...(2)
c + a = 2 x 21 = 42 ...(3)
Adding all the 3 equalities
2a + 2b + 2c = 120
a + b + c = 60 --- (4)
From eq. (2) and (4)
a = 22
From eq. (1) and (4)
b = 18
From eq. (4)
c= 20
? Age of A = 22 years
Age of B = 18 years
Age of C = 20 years
Correct Answer: 50 years
Explanation:
Total age of Ram and shyam 5 years ago
= 2 x 20 = 40 years
? Total age of Ram and Shyam at present
= 40 + 5 + 5 = 50 years
Mohan's age now =90 - 50 years = 40 years
Mohan's age 10 years hence = 40 + 10 years
= 50 years
Correct Answer: 48
Explanation:
Let's eight sequentially number are x, x + 1, x + 2, x + 3, x + 4, x + 5, x + 6 and x + 7.
According to the question [(x + 3) + (x + 4)]/2 = 6
? (2x + 7)/2 = 6 ? 2x + 7 = 12
? 2x = 5 ? x = 5/2
? Sum of all eight numbers = x + x + 1 + x + 2 + x + 3 + x + 4 + x + 5 + x + 6 + x + 7
= 8x + 28
= 20 + 28
= 48
Correct Answer: 30
Explanation:
Let the four consecutive even number are x, ( x+2), (x+4), (x+6).
Clearly this is a series of consecutive even numbers
According to the formula,
Average of consecutive numbers = (first number + last number)/ 2
? 27 = [x + (x + 6)]/2
? x + 3 = 27
? x =24
? Greatest number = 4th consecutive even number = (x + 6) = 24 + 6 = 30
Correct Answer: ? 11000
Explanation:
Total cost of 30 TV sets = ? 300000
Total cost of 15 TV sets = 9000 x 15 = 135000
Total cost of remaining 15 TV sets = 300000 - 135000 = 165000
? Average cost of remaining TV sets = 165000/15 = ? 11000
Correct Answer: 10yr
Explanation:
Total age of 30 girls = 30 x 13 = 390 yr
Total age of 18 girls = 18 x 15 = 270 yr.
? Age of remaining 12 girls = 390 - 270 = 120 yr
? Required average = 120/12 = 10 yr
Correct Answer: 2499
Explanation:
Let the numbers A, B, C, and D are N , N+1, N + 2 and N + 3, respectively.
According to the question,
[N + (N+1) + (N+2) + (N+3)] / 4 = 49.5
? 4N + 6 = 4 x 49.5
? 4N = 198 - 6 ? N = 192/4
? N = 48
The required product = B x D
= (N + 1) x (N + 3)
= (48 +1) (48 +3 )
= 49 x 51
= 2499
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