seven times a two digit number is equal to four times the number obtained by reversing the order of its digits if the difference between the digits is 3 , find the number

let the two digit no. be 10x + y

then 7 (10 x +y) = 4(10y + x) ------------> 70 x + 7y = 40y + 4x -------> 66x = 33y ----------> y = 2x .....(1)

y -x = 3 ....(2)

2x -x =3 (substitute the value of y from (1) )

x =3

or, y -3=3 y = 6

so the no. 10x +y = 10*3 + 6 = 30 +6 = 36