Question

Seven times a two digit number is equal to to four times the number obtained by reversing the digits. If the diffeence between the two nimbers is 3. Find the number

Answer 1

• let the one's and ten's digit no. be X and y . Required no.=10x+y reversed no. =10y+x , therefore , 7(10x+y)=4(10y+x) => 70x+7y=40y+4x => 70x-4x=40y-4y => 66x=36y=>66x-36y=0=> 6(11x-6y)=0 first equation --> 11x-6y=0 , second equation -->x-y=3 11x-x-6y+6y=0-18=> 10x=-18x=-9/5 then put the value of x and find y

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.