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EgmatQuantExpert
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If for the past ‘n’ matches, the average runs scored by Steve is 65 ru Updated on: 12 Aug 2018, 23:05
Originally posted by EgmatQuantExpert on 04 Jul 2018, 06:50.
Last edited by EgmatQuantExpert on 12 Aug 2018, 23:05, edited 2 times in total.
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B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

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15% (low)

Question Stats:

77% (01:23) correct 23% (01:48) wrong based on 295 sessions

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Solve any Mean and Standard deviation question under a minute- Exercise Question #3

3-If for the past ‘n’ matches, the average runs scored by Steve is 65 runs. If today’s century increased his overall average to 70 runs. What is the value of n?

Options

    a) 5
    b) 6
    c) 7
    d) 8
    e) 9

To solve question 4: Question 4


To read the article: Solve any Mean and Standard deviation question under a minute
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B
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If for the past ‘n’ matches, the average runs scored by Steve is 65 ru Updated on: 07 Jul 2018, 07:11
Originally posted by EgmatQuantExpert on 04 Jul 2018, 06:51.
Last edited by EgmatQuantExpert on 07 Jul 2018, 07:11, edited 1 time in total.
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Solution



Given:

    • Average run scored by Steve in past ‘n’ matches= 65.
    • In today’s match, he scored a century.
    • New average after he hit the century is 70 runs.

To find:
    • The value of n
.

Approach and Working:

Method-1

    • \(\frac{Sum\ of\ run\ in\ n\ matches}{n}= 65\)
      o Sum of runs in n matches= 65n

    • \(\frac{Sum\ of\ runs\ in\ n\ matches+100}{n+1}= 70\)
      o 65n+100= 70n+70
      o 5n= 50
      o n=6

Hence, the correct answer is option B.
Answer: B
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If for the past ‘n’ matches, the average runs scored by Steve is 65 ru 04 Jul 2018, 07:42
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EgmatQuantExpert
Solve any Mean and Standard deviation question under a minute- Exercise Question #3

3-If for the past ‘n’ matches, the average runs scored by Steve is 65 runs. If today’s century increased his overall average to 70 runs. What is the value of n?

Options

    a) 5
    b) 6
    c) 7
    d) 8
    e) 9
\(65n + 100 = 70(n + 1)\)

Or, \(65n + 100 = 70n + 70\)

Or, \(5n = 30\)

Or, n = 6 , Answer must be (B)
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If for the past ‘n’ matches, the average runs scored by Steve is 65 ru 04 Jul 2018, 07:53
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Equation is one way.
Another way is to think about the the impact 100 had on 65's which increased it to 70.
Since the new average is 70 , the excess score for the last match is 100-70 = 30.
We have 30 runs which we can distribute to the previous matches to bring it up to 70.
Since each score needs to be increased by 5 , we get 30/5 = 6
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If for the past ‘n’ matches, the average runs scored by Steve is 65 ru 16 Dec 2019, 02:20
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EgmatQuantExpert
Solve any Mean and Standard deviation question under a minute- Exercise Question #3

3-If for the past ‘n’ matches, the average runs scored by Steve is 65 runs. If today’s century increased his overall average to 70 runs. What is the value of n?

Options

    a) 5
    b) 6
    c) 7
    d) 8
    e) 9
Total Increase in score of n matches is 5n
Total increase + new average = New score
5n + 70 = 100
n = 6
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If for the past ‘n’ matches, the average runs scored by Steve is 65 ru 01 Mar 2023, 11:16
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After century, total number matches be=n+1
then , 70(n+1)-65n=100
or, 5n=30
or n=6
So the value of 'n' be=6
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