A two-digit number is $4$ times the sum of its digits. If digits are reversed, the number increases by $18$. Original number is

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Aicharya · Accepted Answer

Digits $a, b$. $10a+b = 4(a+b) \Rightarrow 6a = 3b \Rightarrow b = 2a$. Reversal: $10b+a - (10a+b) = 9(b-a) = 18 \Rightarrow b-a = 2$. With $b=2a$: $a=2, b=4$. Number $= 24$.

A two-digit number is $4$ times the sum of its digits. If digits are reversed, the number increases by $18$.…

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