Seven times a two digit number is equal to four times the number obtained by reversing the order of the digits. If the difference of the digits is 3. determine the number

If the number is 'xy'

Y-x=3

7xy=4yx

y=3+x

7 (10x+y) = 4 (10y+x)

70x+7y=40y+4x

3+x=y

70x+7 (3+x) = 40 (3+x) + 4x

70x+21+7x=120+40x+4x

77x+21=120+44x

77x-44x=120-21

33x=99

x=3

y=x+3

y=3+3

y=6

Hence The number is 36 ...