Question
The average of a set of 25
numbers is 98. For the first 14 numbers, the mean is 84, and for the last 8 numbers, the mean is 112. Furthermore, the 17th number is 38.75% smaller than the 16th number, which is 33.33% greater than the 15th number. Calculate the difference between the 15th and 17th numbers.Solution
ATQ, Let 15th number is ‘3n’. So, 16th number = 4/3 × 3n = 4n And, 17th number = 0.6125 × 4n = 2.45n So, 3n + 4n + 2.45n = 98 × 25 – 14 × 84 – 112 × 8 = 378 Or, 9.45n = 378 Or, n = 40 Desired dierence = 3n – 2.45n = 0.55n = 0.55 × 40 = 22
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