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the digits of a two digit number differ by 5 if the digit are interchanged and the resulting number is added to the orginal number we get 121 find the number |
Answer» AnswEr:-Two digits number = 38 Solution:-Let the digit at unit's place be y & digit at ten's place be z where y > z ∴ Two digit number = y + 10z CASE 1:- ⇒ y - z = 5 ⇒ y = z + 5 [Eq.i] Case 2:- ★ Interchanged number:- ⇒ New number = z + 10y According to QUESTION:- ⇒ y + 10z + z + 10y = 121 ⇒ 11y + 11z = 121 ⇒ 11(y + z) = 121 ⇒ y + z = 121/11 ⇒ y + z = 11 ⇒ y = 11 - z [Eq.ii] Comparing both equations - ⇒ z + 5 = 11 - z ⇒ z + z = 11 - 5 ⇒ 2z = 6 ⇒ z = 6/2 ⇒ z = 3 So, digit at ten's place = z = 3 Putting this VALUE in (Eq.i) ⇒ y = 3 + 5 ⇒ y = 8 So, digit at unit's place = y = 8 ★ Two digit number:- ⇒ Number = 8 + 10(3) ⇒ Number = 8 + 30 ⇒ Number = 38 Therefore, |
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