Question

Seven times a two digit number is equal to four times the number obtained byreversing the order of its digits. If the difference of the digits is 3, determine thenumber.

Answer 1

Answer:

36

Step-by-step explanation:

let say number = xy

value of number = 10x + y

reversed number = yx

Value of number = 10y +x

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

=> 70x + 7y = 40y + 4x

=> 66x = 33y

=> 2x = y

y - x = 3

2x - x = 3

x = 3

y = 6

Number = 36

Answer 2

Answer:

36

Step-by-step explanation:

Let the unit digit be a and tenth unit be b .

So , number = 10 b + a

It's said number is seven times is equal to reversing the order of its digit.

= > 7 ( 10 b + a ) = 4 ( 10 a + b )

= > 70 b + 7 a = 40 a + 4 b

= > 66 b = 33 a

= > a = 2 b ... ( i )

Also given numbers' difference is 3 .

a - b = 3  ( ii )

From ( i ) and ( ii ) we get :

a b - b = 3

b = 3

= > a = 6

Hence number = > 30 + 6

= > 36.