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QJEEM23Ma554e: JEE Main 2023 Mathematics - Class 11 JEEM23Ma554e Solution: root of a number is 12 and root of another number is 18 . Then…

50th 50^{\text {th }} root of a number xx is 12 and 50th 50^{\text {th }} root of another number yy is 18 . Then the remainder obtained on dividing (x+y)(x+y) by 25 is ____________.

Step-by-Step Verified Solution

Given x150=12⇒x=1250{x^{{1 \over {50}}}} = 12 \Rightarrow x = {12^{50}}

y150=18⇒y=1850{y^{{1 \over {50}}}} = 18 \Rightarrow y = {18^{50}}

12≡1312\equiv13 (Mod 25)

122≡1912^2\equiv19 (Mod 25)

123≡−312^3\equiv-3 (Mod 25)

129≡−212^9\equiv-2 (Mod 25)

1210≡−112^{10}\equiv-1 (Mod 25)

1250≡−112^{50}\equiv-1 (Mod 25) ..... (i)

Now

18≡718\equiv7 (Mod 25)

182≡−118^2\equiv-1 (Mod 25)

18−50≡−118^{-50}\equiv-1 (Mod 25) ..... (ii)

∴\therefore 1250+1850≡−212^{50}+18^{50}\equiv-2 (Mod 25)

≡23\equiv23 (Mod 25)

∴\therefore Answer = 23

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