RBI Assistant Prelims practice question
3 years from now, Farah's age will be twice the age of her colleague Gopal at that time. 7 years after that point (that is, 10 years from now), the ratio of Farah's age to Gopal's age will be 7:4. Find Gopal's present age.
From a RBI Assistant Prelims Quantitative Aptitude practice set · Quantitative Aptitude
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Correct answer: (A) 18 years
Let present ages be F (Farah) and G (Gopal). After 3 years: F+3 = 2(G+3) => F-2G = 3 ...(i). After 10 years (3+7): (F+10)/(G+10) = 7/4 => 4F-7G = 30 ...(ii). From (i): F=2G+3. Substitute in (ii): 4(2G+3)-7G=30 => 8G+12-7G=30 => G=18. Gopal's present age = 18 years.
हिंदी में प्रश्न
अब से 3 वर्ष बाद, फराह की आयु उस समय उसकी सहकर्मी गोपाल की आयु की दोगुनी हो जाएगी। उस समय के 7 वर्ष बाद (अर्थात अब से 10 वर्ष बाद), फराह की आयु और गोपाल की आयु का अनुपात 7:4 हो जाएगा। गोपाल की वर्तमान आयु ज्ञात कीजिए।
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सही उत्तर: (A) 18 वर्ष
मान लीजिए वर्तमान आयु F (फराह) और G (गोपाल) हैं। 3 वर्ष बाद: F+3 = 2(G+3) => F-2G = 3 ...(i)। 10 वर्ष बाद (3+7): (F+10)/(G+10) = 7/4 => 4F-7G = 30 ...(ii)। समीकरण (i) से F=2G+3, इसे (ii) में रखने पर: 4(2G+3)-7G=30 => 8G+12-7G=30 => G=18। गोपाल की वर्तमान आयु = 18 वर्ष।
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