Question

The sum of digit of a digit no. is 7. if the digit ax reveresed,the new no. increased by 3 equal 4 times the original no. find the no.

Answer 1

Correct Question:-

The sum of digit of a digit no. is 7. if the digit ax reveresed,the new no. increased by 3 equal 4 times the original no. find the no.

Solution :

Let the two digit number be 100 + b

Given that : a + b = 7

a=7-b ....(i)

After reversing the digits , New number 10 b + a .

According to Question :

10b + a + 3 = 4 (100 a + b )

10b + a + 3 = 40 a + 4 b

10b - 4b + 3 = 40 a -a

6b + 3 = 39 a .

39 a - 6b = 3.

273 -3 ( 39 b - 6b)

270= 45 b

$\frac{270}{45} = b$

b = 6.

a = 7 - 6 .

a = 1.

original number = 10 a + b .

= 10(1) + 6

= 10 + 6

= 16 .

Thanks!