Let the number be 10x + y.∴ 10x + y - (10y + x) = 27or 9x - 9y = 27∴ x - y = 3 .......(I)x + y = 13 .......(II)From eqn (I) and (II)x = 8 and y = 5.So the number = 85Therefore, product = 8 x 5 = 40
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)
The least number to be added to the numbers to make them divisible by 9 is equal to the difference of the least multiple of 9 greater than the sum of the digits and sum of the digits.Sum of digits = 15.Nearest multiple of 9 greater than sum of digits = 18.Hence 3 has to be added.