Q6 of 176 Page 21

Find the two numbers whose A.M. is 25 and GM is 20.

⇒


⇒ G.M = √ab


Given A.M=25, G.M = 20.


⇒ √ab = 20 …….(1)


⇒ …….(2)


⇒ a + b = 50


⇒ a = 50 – b


Putting the value of ‘a’ in equation (1), we get,


⇒


⇒ 50b – b2 = 400


⇒ b2 – 50b + 400 = 0


⇒ b2 – 40b – 10b + 400 = 0


⇒ b(b – 40) – 10(b – 40) = 0


⇒ b = 40 or b = 10


⇒ If b = 40 then a = 10


⇒ If b = 10 then a = 40


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