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Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Sapare bhavani bai
Correct Answer: 12 years Description for Correct answer: Let the age of Sagun and shristi be x and y years respectively ∴∴According to question. x×yx×y = 240 ...(i) 2y = x + 4 ...(ii) From equations (i) and (ii) 2y = 240y240y + 4 , 2y-240y240y=4 2y2y2-240=4y 2y2y2-4y-240=0 ∴∴(−4)±16+4×2×240−−−−−−−−−−−√2×2(−4)±16+4×2×2402×2 =4±1936−−−−√44±19364 =4±4444±444 = 484484=12 years