Question
The average of 10 numbers is 18. When two new numbers
'a' and 'b' are added, the average increases by 2. If a - b = 30, find the value of b.Solution
ATQ, Sum of 10 numbers = 10×18=180 Sum of 12 numbers = 12×20=240 So, a+b=240−180=60 ----------(i) And, a−b=30 -----------(ii) Solving (i) and (ii), we get: a+b=60 a−b=30 Adding these equations: 2a=90 a=45 Substituting a=45 into equation (i): 45+b=60 b=15
More Average Questions
I. 6x2 - 47x + 77 =0
II. 6y2 - 35y + 49 = 0
I. 8x² - 74x + 165 = 0
II. 15y² - 38y + 24 = 0
I. 3p² + 13p + 14 = 0
II. 8q² + 26q + 21 = 0
I). 5p2 - p - 4 = 0
II). q2 - 12q + 27 = 0
I. 5x² - 28x + 39 = 0
II. 2y² - 13y + 20 = 0
I. 8x² + 2x – 3 = 0
II. 6y² + 11y + 4 = 0
I. 2x2 – 5x - 12 = 0
II. y2 – 11y + 30 = 0
I. 2x² - 9x + 10 = 0
II. 3y² + 11y + 6 = 0
I. x2 + 24x + 143 = 0
II. y2 + 12y + 35 = 0
I). p2 = 81
II). q2 - 9q + 14 = 0