Question
In a classroom, the average score of 15 students on a
test is 44 points. If 5 new students, each with an average score of 'x' points, join the class, and 8 students, each with an average score of '(x – 6)' points, leave the class, the new average score of the 12 remaining students becomes '(x – 1)' points. What is the total score of these 12 students?Solution
ATQ, The sum of the score of 15 students on a test is = 44 × 15 = 660 The sum of the the score of 5 students is = 5 × a = 5a The sum of the score of 8 students is = 8(a – 6) = (8a – 48) The sum of the score of 12 students is = 12(a – 1) = (12a – 12) According to the question, 660 + 5a – (8a – 48) = 12a – 12 660 + 5a – 8a + 48 = 12a – 12 660 + 48 + 12 = 12a + 3a 720 = 15a a = 48 a = 48 Average score of 12 students is = 48 – 1 = 47 The sum of the score of 12 students is = 47 × 12 = 564
4, 9, 35, 159, 951, 6931
78, 88, 118, 208, 468, 1288
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1520, 1760, 2120, 2720, 2840, 2560
- 82, 65, 84, 61, 91, 59
Find the wrong number in the given number series.
7, 9, 16, 12, 25, 15, 3612, 220, 322, 376, 402, 415
Find the wrong number in the given number series,
9, 60, 299, 1199, 3599, 7199
18 45 90 235 450 1125 2250
...Find the wrong number in the series.
2, 4, 12, 10, 30, 16, 56112, 236, 374, 546, 790, 1376
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