Solve the following word problems.
A two digit number and the number with digits interchanged add up to 143. In the given number the digit in unit’s place is 3 more than the digit in the ten’s place. Find the original number.
Let the digit in unit’s place is x
and that in the ten’s place is y
The number obtained by interchanging the digits is 
According to first condition two digit number + the number obtained by interchanging the digits = 143
From the second condition,
digit in unit’s place = digit in the ten’s place + 3
Adding equations (I) and (II)
Putting this value of x in equation (I)
x + y = 13
The original number is 10
