Question

a two digit number is 3 more than 4 times the sum of its digits . if 18 is added to the number the digits are reversed. find the number

Answer 1

Let the ten's digit and unit's digit be x and y respectively

Number formed = 10x+y

According to the question : -
A two digit number is 3 more than 4 times the sum of its digits

10x+y = 3+4(x+y)
2x - y = 1 -- 1

According to the question : -
If 18 is added to the number the digits are reversed

18 + 10x + y = 10y + x
x - y = -2. -- 2

By subtracting equation 1 and 2
x = 3

By substituting value of x in equation
y = 5

Number = 10x + y
= 30 + 5
= 35

Answer 2

Here is your solutions


Let ones place digit be x .

Tens place digit be y .

Original number = 10y + x

Number formed by reversing the digits = 10x + y

A two digit number is 3more than 4times the sum of its digits .

A/q

=>10y + x = 4(x + y) + 3 
=>10y + x − 4x − 4y = 3
 => 6y − 3x = 3 
=>2y − x = 1..................(1) 

Again when 18 is added to the number then digits get interchanged. 

(10y + x) + 18 = 10x + y 

=>9x − 9y = 18
=> x − y = 2...................(2) 

On adding equation (1) and (2):-

 2y − x +(x-y)= 1+2
2y-x+x-y = 3
Y = 3

Putting the value of y im equation (2)

=> x − y = 2
=>x- 3 =2
=>x= 2+3
=>x =5

Hence

Number = 10y +x= 10×3+5=35

Hope it helps you