# Example 19 - Chapter 2 Class 8 Linear Equations in One Variable

Last updated at June 21, 2018 by Teachoo

Last updated at June 21, 2018 by Teachoo

Transcript

Example 19 Present ages of Anu and Raj are in the ratio 4 : 5. Eight years from now the ratio of their ages will be 5:6. Find their present ages. Given that, Present ages of Anu and Raj are in the ratio 4 : 5 (ππππ πππ‘ πππ ππ π΄ππ’)/(ππππ πππ‘ πππ ππ π ππ)=4/5 Let present age of Anu = 4x Years & present age of Raj = 5x years After 8 years from now, Anuβs age = (4x + 8) years Rajβs age = (5x + 8) years Given that, Ratio of ages after 8 years is 5:6 (π΄ππ’^β² π πππ πππ‘ππ 8 π¦ππππ )/(π ππ^β² π πππ πππ‘ππ 8 π¦ππππ )=5/6 (4π₯ + 8)/(5π₯ + 8)=5/6 By cross-multiplication 6 (4π₯ + 8) = 5 (5π₯ + 8) (6 Γ 4)π₯+ (6 Γ 8) = (5 Γ 5)π₯ + (5 Γ 8) 24π₯+ 48 = 25π₯+ 40 48 β 40 = 25π₯β 24π₯ 8 = π₯ π₯ = 8 β΄ Present age of Anu = 4π₯ = 4 Γ 8 = 32 years & Present age of Raj = 5π₯ = 5 Γ 8 = 40 Years

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Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.