Question

Sum of digits of a no is 7 if 9 is subtracted from the no.the digits get reversed find the No

Answer 1

Let the tens digit be x, unit be 7-x original no. equals to 10x+7-x and reversible no. = 70x-10 a/q =10x+7-x-9=70-10x+x by solve the equation we get x=4 therefore no. is 43

Answer 2

♧♧HERE IS YOUR ANSWER♧♧

Let, the digits are a and b.

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

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

By the given condition :

(10a + b) - 9 = 10b + a

=> 9a = 9b + 9

=> a = b + 1 .....(i)

and

a + b = 7 .....(ii)

From (i) and (ii), eliminating b, we get :

b + 1 + b = 7

=> 2b = 6

=> b = 3

From (i), putting b = 3, we get :

a = 3 + 1 = 4

Therefore, the required number is 43.

♧♧HOPE THIS HELPS YOU♧♧