Question

Cricket player Dhoni's average in first 30 matches was 72 runs. After 31 match?average raised as 73 runs, How many runs did he makin
(A)
100
(B) 103
(C)
74
(D) 108​

Answer 1

Answer:

The runs scored in 31st match are 103.

Step-by-step explanation:

Gívєn -

Dhoni's average in First 30 matches = 72 runs

After 31st match, average was raised to = 73 runs

Tσ fínd -

Runs he made in the 31st match

Sσlutíσn -

Case I

First, find the total runs scored in 30 matches :

Here ;

• Average = 72
• Total Observations = 30
• Sum of Observations = x

★ We know - $\sf{Mean = \frac{Sum \: of \: Observations}{No. \: of \: Observations}}$

$\sf{\implies} \: 72 = \dfrac{x}{30}$

$\sf{\implies} \: x = 72 \times 30$

$\sf{\implies} \: x = 2160$

Runs score in 30 matches are 2160 runs.

$\rule{300}{1.5}$

Case II

Let the runs scored in the 31st match be as y

Here ;

• Average = 73
• Total Observations = 31
• Sum of Observations = (2160 + y)

$\sf{\implies} \: 73 = \dfrac{(2160 + y)}{31}$

$\sf{\implies} \: 73 \times 31 = 2160 + y$

$\sf{\implies} \: 2263 = 2160 + y$

$\sf{\implies} \: y = 2263 - 2160$

$\sf{\implies} \: y = 103$

Added runs = 103

$\therefore$ The runs scored in 31st match are 103.

Answer 2

Answer:

(B) 103

Step-by-step explanation:

>>>Dhoni Played 30 Matches

            Average : 72

      Let us Assume That every Match Dhoni Scored 72 Runs

>>>Dhoni on His 31st Match

            Average: 73

!! Here We need To know that

         if dhoni scores 73 Runs in all 31 matches.. His average will be 73

     SO WE KNOW 31st MAtch Score is 73

     We Want To ADD 1 run to Remaining 30 Matches

    (30 matches * 1 run=30 runs)

By Adding it to 31st Match Score (73 + 30 = 103 Runs)