Question

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

Answer 1

hope it help you....

Answer 2

Let the 1st and 2nd digits no. be y and x respectively.

According to question...

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

70x + 7y = 40y + 4x

70x - 4x = 40y - 7y

66x = 33y

y = 2x.......(1)

y - x = 3.....(2) (given in question)

By substitution method......

Put the value of (y) in equation (2)....

y - x = 3

2x - x = 3

(x = 3).....

From eqs. (1), we get..

y = 2x

y = 2(3)

(y = 6)......

Therefore, a two digit number will be

10x + y

10(3) + 6

30 + 6

36.....

And number obtained will be

10y + x

10(6) + 3

60 + 3

63

Since, 63 and 36 is in reversing order.....