Table Charts Questions & Answers - Page 2

Total number of students who passed in annual exams in a section

= [ (No. of students who failed in half-yearly but passed in annual exams) + (No. of students who passed in both exams) ] in that section

Therefore Success rate in annual exams in Section A

= [ No. of students of Section A who passed in annual exams/Total number of students in Section A x 100 ] %

= [ (14 + 64)/(28 + 14 + 6 + 64) x 100 ] %

= [ 78/112 x 100 ] %

= 69.64%.

Similarly, success rate in annual exams in:

Section B [ (12 + 55)/(23 + 12 + 17 + 55) x 100 ] % = [ 67/107 x 100 ] % = 62.62%.

Section C [ (8 + 46)/(17 + 8 + 9 + 46) x 100 ] % = [ 54/80 x 100 ] % = 67.5%

Section D [ (13 + 76)/(27 + 13 + 15 + 76) x 100 ] % = [ 89/131 x 100 ] % = 67.94%

Clearly, the success rate in annual examination is maximum for Section A

Pass percentages in at least one of the two examinations for different sections are:

For Section A [ (14 + 6 + 64)/(28 + 14 + 6 + 64) x 100 ] % = [ 84/112 x 100 ] % = 75%

For Section B [ (12 + 17 + 55)/(23 + 12 + 17 + 55) x 100 ] % = [ 84/107 x 100 ] % = 78.5%

For Section C [ (8 + 9 + 46)/(17 + 8 + 9 + 46) x 100 ] % = [ 63/80 x 100 ] % = 78.75%

For Section D [ (13 + 15 + 76)/(27 + 13 + 15 + 76) x 100 ] % = [ 104/131 x 100 ] % = 79.39%

Clearly, the pass percentage is maximum for Section D.

Since the classification of the students on the basis of their results and sections form independent groups, so the total number of students in the class:

= (28 + 23 + 17 + 27 + 14 + 12 + 8 + 13 + 6 + 17 + 9 + 15 + 64 + 55 + 46 + 76)

= 430

Number of students who passed half-yearly exams in the school

  = (Number of students passed in half-yearly but failed in annual exams)

      + (Number of students passed in both exams)

  = (6 + 17 + 9 + 15) + (64 + 55 + 46 + 76)

  = 288.

Also, Number of students who passed annual exams in the school

  = (Number of students failed in half-yearly but passed in annual exams)

      + (Number of students passed in both exams)

  = (14 + 12 + 8 + 13) + (64 + 55 + 46 + 76)

  = 288.

Since, the number of students passed in half-yearly = the number of students passed in annual exams. Therefore, it can be inferred that both the examinations had almost the same difficulty level.

Thus Statements (a), (b) and (d) are false and Statement (c) is true.

From the table it is clear that the sales of 7AH batteries have been decreasing continuously from 1992 to 1997

The percentages of sales of 4AH batteries to the total sales in different years are:

For 1992 = ( 75/543 x 100 ) % = 13.81%

For 1993 = ( 90/528 x 100 ) % = 17.05%

For 1994 = ( 96/525 x 100 ) % = 18.29%

For 1995 = ( 105/510 x 100 ) % = 20.59%

For 1996 = ( 96/465 x 100 ) % = 19.35%

For 1997 = ( 105/495 x 100 ) % = 21.21%

For 1998 = ( 115/605 x 100 ) % = 19.01%

Clearly, the percentage is maximum in 1997.

Required difference = [(84 - 45) x 1000] = 39000

The total sales (in thousands) of all the seven years for various batteries are:

For 4AH = 75 + 90 + 96 + 105 + 90 + 105 + 115 = 676

For 7AH = 144 + 126 + 114 + 90 + 75 + 60 + 85 = 694

For 32AH = 114 + 102 + 75 + 150 + 135 + 165 + 160 = 901

For 35AH = 102 + 84 + 105 + 90 + 75 + 45 + 100 = 601

For 55AH = 108 + 126 + 135 + 75 + 90 + 120 + 145 = 799.

Clearly, sales are maximum in case of 32AH batteries.

Required percentage = [ (145 - 108)/108 x 100 ] %

= 34.26%

≈ 34%

Required percentage = [ (82 + 70 + 48 + 65 + 55)/(640 + 560 + 400 + 525 + 350) ] %

= [ 320/2475 x 100 ] %

= 12.93%

≈ 13%