Question

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

Answer 1

The answer is given below :

Let us consider that the number has a as tens digit and b as ones digit.

Then, the number is (10a + b).

When the digits are reversed, the number is (10b + a).

Given that, seven times of the original number is equal to the four time of the reversed digits number.

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

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

=> 66a = 33b

=> 2a - b = 0 .....(i)

Given, the difference of the digits is 3.

=> b - a = 3 .....(ii)

Now, adding (i) and (ii), we get

a = 3

Putting a = 3 in (i), we get

b = 6

Therefore, the required number is 36.

Thank you for your question.

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.