In one day, a rickshaw puller earned ₹. \[137\dfrac{1}{2}\]. Out of this money. He spent ₹. $56\dfrac{3}{4}$ on food. How much money is left with him?

Hint: To get money left with a rickshaw puller we calculate the difference of the money earned and money spent.

Complete step by step solution:
Money earned by a rickshaw puller on a one day is ₹. \[137\dfrac{1}{2}\].
Converting mixed fraction into improper fraction
\[
  \dfrac{{137 \times 2 + 1}}{2} \\
   = \dfrac{{274 + 1}}{2} \\
   = \dfrac{{275}}{2} \\
 \]
Money spent on food by rickshaw puller is ₹. $56\dfrac{3}{4}$
Converting mixed fraction into improper fraction
$
  \dfrac{{56 \times 4 + 3}}{4} \\
   = \dfrac{{224 + 3}}{4} \\
   = \dfrac{{227}}{4} \\
 $

Money left with a rickshaw puller is the difference of the money earned on one day and money spent on the same day. Therefore calculating the difference of $\dfrac{{275}}{2}$ and $\dfrac{{227}}{4}$.
$\dfrac{{275}}{2} - \dfrac{{227}}{4}$, taking l.c.m. of denominators.
i.e. l.c.m. of $2$ and $4$ is $4$ as $4$ comes in the table of $2$.
$ \Rightarrow \dfrac{{275 \times 2 - 227}}{4}$
$ \Rightarrow \dfrac{{550 - 227}}{4}$
\[ \Rightarrow \dfrac{{323}}{4}\]
Writing improper fraction into mixed fraction.
$80\dfrac{3}{4}$
Hence, from above we see the amount left with the rickshaw puller after earning ₹. \[137\dfrac{1}{2}\] and spending ₹. $56\dfrac{3}{4}$ on food is ₹. $80\dfrac{3}{4}$

Note: Money saved is always equal to the difference of the money earned and money spent by any one.