A two-digit number is 3 more than 4 times the sum of its digits. If 18 is added to the number, the digits are reversed. Find the number. Let the tens and the units digits of the required number be x and y, respectively.Required number = (10x + y)10x + y = 4(x + y) + 3⇒10x + y = 4x + 4y + 3⇒ 6x – 3y = 3⇒ 2x –y = 1 ……….(i)Again, we have:10x + y + 18 = 10y + x⇒9x – 9y = -18⇒x – y = -2 ……..(ii)On subtracting (ii) from (i), we get:x = 3On substituting x = 3 in (i) we get2 × 3 –y = 1⇒ y = 6 – 1 = 5Required number = (10x + y) = 10 × 3 + 5 = 30 + 5 = 35 Hence, the required number is 35. Concept: Pair of Linear Equations in Two Variables Is there an error in this question or solution? |