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Official Soldier GD Paper: [Rajput Regt Centre, Fategarh (Lucknow)] - 28 March 2021

Option 4 : 41

Given

A batsman in his 12th inning makes a score of 63 runs and there by increase his average score by 2

Concept used

Average = Sum of the observation/Total observation

Calculation

Let the total number of runs in 11 innings be "x".

the average number of runs in 11 innings is x/11

Let the total number of runs in 12 innings after scoring 63 runs in 12th innings be x + 63.

Average number of runs in 12th innings is = (x + 63)/12

⇒ (x + 63)/12 = x/11 + 2

⇒ (x + 63)/12 = (x + 22)/11

⇒ 11(x + 63) = 12(x + 22)

⇒ 11x + 693 = 12x + 264

⇒ 693 - 264 = 12x - 11x

⇒ 429 = x

Average of his score after 12 innings

⇒ (x + 63)/12

⇒ (429 + 63)/12

⇒ 41

∴ His average after the 12th innings is 41.

__Alternate Method__

A batsman in his 12th inning makes a score of 63 runs

His average increases by 2 runs

Increased runs = 11 × 2

Increased runs = 22 runs

His average after 12 innings

⇒ 63 - 22

⇒ 41