If 1 carton of mangoes weigh $2\frac{4}{5}$ kg, how much will 15 such cartons weigh (in kg)?

The correct option is C 42
Weight of 1 carton mangoes = $2\frac{4}{5}$ kg
Weight of 15 such cartons = 15 x $2\frac{4}{5}$ kg
= 15 x $\frac{14}{5}$ kg
= 42 kg