If 45 is added to the number, the digits are reversed. A 2-digit number is 5 more than 3 times the sum of its digits. Find the number.?
Answers
Answer:
9 is the correct answer
Step-by-step explanation:
If 45 is added to the number, the digits are reversed. A 2-digit number is 5 more than 3 times the sum of its digits. Find the number.?
Let the Number be (10x + y) where y is One's Digit and x is Ten's Digit.
☢ According to the Question Again :
↠ Number = 5 + 3(Sum of Digits)
↠ (10x + y) = 5 + 3(x + y)
↠ 10x + y = 5 + 3x + 3y
↠ 10x – 3x + y – 3y = 5
↠ 7x – 2y = 5 ⠀— eq.( I )
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☢ According to the Question Again :
↠ Original No. + 45 = Reverse No.
↠ (10x + y) + 45 = (10y + x)
↠ 10x + y + 45 = 10y + x
↠ 10x – x + y – 10y + 45 = 0
↠ 9x – 9y + 45 = 0
↠ 9x – 9y = – 45
↠ 9(x – y) = – 45
Dividing both term by 9
↠ x – y = – 5
↠ x = (y – 5) ⠀— eq.( II )
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★ Putting the value of x in eq. ( I ) :
⇢ 7x – 2y = 5
⇢ 7(y – 5) – 2y = 5
⇢ 7y – 35 – 2y = 5
⇢ 5y = 5 + 35
- Dividing both term by 5
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★ Putting the value of y in eq. ( II ) :
⇢ x = (y – 5)
⇢ x = (8 – 5)
◗ Number = (10x + y) = (10 × 3 + 8) = 38