Question

in a two digits number is 3 more than 4 time the sum of its digits find the number​

Answer 1

Solution:

Let the tens and the units digits of the required number be x and y, respectively.

Required number = (10x + y)

10x + y = 4(x + y) + 3

→ >10x + y = 4x + 4y + 3

6x - 3y = 3

⇒ 2x -y = 1

.(i)

Again, we have:

10x + y + 18 = 10y + x

9x - 9y = -18

⇒x - y = -2

...(ii)

On subtracting (ii) from (i), we get:

x = 3

On substituting x = 3 in (i) we get

2x3-y = 1

⇒ y = 6-1=5

Required number = (10x + y) = 10 x 3 +5 = 30 + 5 = 35

Hence, the required number is 35.

Answer 2

Let the tens and unit digit of number are x,y

First condition :

⇒10x+y=3+4(x+y)

⇒6x−3y=3

⇒2x−y=1

Second condition :

⇒10x+y+18=10y+x

⇒x−y=−2

Subtract resultant equations ;

⇒x=3

⇒y=5

∴two digit number =35