Question 15 - MCQs from NCERT Exemplar - Chapter 3 Class 10 Pair of Linear Equations in Two Variables

Last updated at April 16, 2024 by

The father’s age is six times his son’s age. Four  years hence, the age of the father will be four times  his son’s age. The present ages, in years, of the son  and the father are, respectively: 

(a)4 and 24  

(b) 5 and 30 

(c) 6 and 36  

(d) 3 and 24

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Question 15 The father’s age is six times his son’s age. Four years hence, the age of the father will be four times his son’s age. The present ages, in years, of the son and the father are, respectively: 4 and 24 (b) 5 and 30 (c) 6 and 36 (d) 3 and 24 Let the Present Age of Son = x years Present Age of Father = y years Given that Father’s age is 6 times son’s age y = 6x Four years later, Age of the father will be four times his son’s age Age of father after 4 years = 4 × Age of son after 4 years y + 4 = 4 × (x + 4) y + 4 = 4x + 16 y = 4x + 16 − 4 y = 4x + 12 Putting y = 6x from (1) 6x = 4x + 12 6x − 4x = 12 2x = 12 x = 12/2 x = 6 Putting x = 6 in (1) y = 6x y = 6 × 6 y = 36 Thus, x = 6, y = 36 So, the correct answer is (C)

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo