The weights of three packets are $2\dfrac{3}{4}$ kg, $3\dfrac{1}{3}$ kg and $5\dfrac{2}{5}$ kg. Find the total weight of all the three packets.

Weights of three packets = $2\dfrac{3}{4}$ kg, $3\dfrac{1}{3}$ kg and $5\dfrac{2}{5}$ kg.

Total weight = $2\dfrac{3}{4} + 3\dfrac{1}{3} + 5\dfrac{2}{5}$

LCM of 4, 3 and 5 = 60.

$\Rightarrow \dfrac{11}{4} + \dfrac{10}{3} + \dfrac{27}{5}\\[1em] \Rightarrow \dfrac{11 \times 15}{4 \times 15} + \dfrac{10 \times 20}{3 \times 20} + \dfrac{27 \times 12}{5 \times 12}\\[1em] \Rightarrow \dfrac{165}{60} + \dfrac{200}{60} + \dfrac{324}{60}\\[1em] \Rightarrow \dfrac{165 + 200 + 324}{60}\\[1em] \Rightarrow \dfrac{689}{60}\\[1em] \Rightarrow 11\dfrac{29}{60} \text{ kg}$

Hence, the total weight of the three packets = $11\dfrac{29}{60}$ kg.