Average
- The average of the first 7 integers in a series of 13 consecutive odd integers is 37. What is the average of the entire series?
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Given that , Average of 7 consecutive odd integers = 37
∴ Fourth odd number = 37
∴ First odd number = 31
13th odd number = 31 + 24 = 55Correct Option: D
Given that , Average of 7 consecutive odd integers = 37
∴ Fourth odd number = 37
∴ First odd number = 31
13th odd number = 31 + 24 = 55∴ Required average = 31 + 55 = 86 = 43 2 2
- If the difference between the average of x, y and y, z is 12, then the difference between x and z is :
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According to the question,
x + y - y + z = 12 2 2
Correct Option: A
According to the question,
x + y - y + z = 12 2 2 ⇒ X - Z = 12 2
⇒ x – z = 2 × 12 = 24
- The average of 100 observations was calculated as 35. It was found later, that one of the observations was misread as 83 instead of 53. The correct average is :
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According to question ,
Difference = 83 – 53 = 30
Incorrect observation > Correct observation∴ Required average = 35 - 30 100
Correct Option: B
According to question ,
Difference = 83 – 53 = 30
Incorrect observation > Correct observation∴ Required average = 35 - 30 = 35 - 0.3 = 34.7 100
- The average of 25 results is 20. The average of first 12 results is 15 and that of the last 12 results is 18. Then, the 13th result is :
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Here , The average of 25 results = 20.
The average of first 12 results = 15
and average of the last 12 results = 18.
Value of 13th result = 25 × 20 – 12 × 15 – 12 × 18Correct Option: C
Here , The average of 25 results = 20.
The average of first 12 results = 15
and average of the last 12 results = 18.
Value of 13th result = 25 × 20 – 12 × 15 – 12 × 18
Value of 13th result = 500 – 180 – 216
Hence , Value of 13th result = 104
- The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is :
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B’s weight = (A + B)’s weight + (B + C)’s weight – (A + B + C)’s weight
B’s weight = (40 × 2 + 2 × 43 – 45 × 3) kg.
B’s weight = (80 + 86 – 135) kg.Correct Option: A
B’s weight = (A + B)’s weight + (B + C)’s weight – (A + B + C)’s weight
B’s weight = (40 × 2 + 2 × 43 – 45 × 3) kg.
B’s weight = (80 + 86 – 135) kg.
B’s weight = 31 kg.
