On one day, a labourer earned ₹ 125. Out of this money, he spent ₹ $68\dfrac{1}{2}$ on food, ₹ $20\dfrac{3}{4}$ on tea and ₹ $16\dfrac{2}{5}$ on other eatables. How much does he save on that day?

Given, expenses = ₹ $68\dfrac{1}{2}$ on food, ₹ $20\dfrac{3}{4}$ on tea and ₹ $16\dfrac{2}{5}$ on other eatables

Total

$\Rightarrow 68\dfrac{1}{2} + 20\dfrac{3}{4} + 16\dfrac{2}{5}\\[1em] \Rightarrow \dfrac{137}{2} + \dfrac{83}{4} + \dfrac{82}{5}\\[1em]$

LCM of 2, 4 and 5 = 20

$\Rightarrow \dfrac{137 \times 10}{2 \times 10} + \dfrac{83 \times 5}{4 \times 5} + \dfrac{82 \times 4}{5 \times 4}\\[1em] \Rightarrow \dfrac{1370}{20} + \dfrac{415}{20} + \dfrac{328}{20}\\[1em] \Rightarrow \dfrac{1370 + 415 + 328}{20} \\[1em] \Rightarrow \dfrac{2113}{20} \\[1em] \Rightarrow 105\dfrac{13}{20}$

Savings = Income − Total expenses

$\text{Savings }= 125 - \dfrac{2113}{20}\\[1em] = \dfrac{125 \times 20}{20} - \dfrac{2113}{20}\\[1em] = \dfrac{2500}{20} - \dfrac{2113}{20}\\[1em] = \dfrac{2500 - 2113}{20}\\[1em] = \dfrac{387}{20}\\[1em] = 19\dfrac{7}{20}$

Hence, savings = $₹19\dfrac{7}{20}$.