Let the digits be x and yTherefore, x + y = 12 .............(1)(10y + x) - (10x + y) Therefore, y - x = 4............. (2)Solving (1) and (2), y = 8 Therefore, x = 4There are two possible numbers 48 and 84. So the lowest no. is 48.
Let the number be 10x + y∴ 3x = 4y ......(1)From (I),x + y = 14 .....(2)Solving equations (1) and (2),x = 8, y = 6∴ Number = 86 From (II)y = 75/100 x x ∴ 3x = 4y.Which is the same as eqn (1)