Question

Mother gave 60 Rs. to Lissy for buying books. She gave back Rs. 13. For how much money did she buy books?

Answer 1

Hint: We form the mathematical expression for the given conditions. We get $ x+13=60 $ where the variable is the money used for buying books. We simplify the equation to find the final solution.

Complete step-by-step answer:
Mother gave 60 Rs. to Lissy for buying books. She gave back Rs. 13. This means that she used the rest of the money for buying books. Let it be a variable $ x $ .
Forming the mathematical expression, we get $ x+13=60 $ .
Simplifying we need to find the value of $ x $ .
The given equation $ x+13=60 $ is a linear equation of $ x $ . We need to simplify the equation by solving the variables and the constants separately.
All the terms in the equation of $ x+13=60 $ are either variable of $ x $ or a constant. We first separate the variables.
We take the constants all together to solve it.
 $ \begin{align}
  & x+13=60 \\
 & \Rightarrow x=60-13 \\
\end{align} $
There are two such constants which are 60 and 13.
Now we apply the binary operation of subtraction to get
 $ \Rightarrow x=60-13=47 $
Therefore, Lissy used Rs. 47 for buying books.

Note: When we add 47 and 13, we get back $ 47+13=60 $ which satisfies the given condition of total value given to Lissy by her mother.