Question

a factory has two automatic brick packaging machines. One packs 24000 bricks per hour and the other packs 12000 bricks per hour. How much time will it take to pack a total of 12000 bricks if both the machines are put to use?

Answer 1

Answer :

Given one machine packs 24000 bricks per hour , So

Other machine packs 12000 bricks per hour , So

Both machines pack 36000 bricks per hour

Both machines packs 1 brick in $\frac{1}{36000}hr$
Therefore
Both machines packs 12000 bricks in $\frac{1}{36000}\times 12000=\frac{1}{3}\mathrm{hour}=\frac{1}{3}\times 60\mathrm{minutes}=\mathbf{20}\mathbf{}\mathbf{minutes}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{(}\mathbf{}\mathbf{Ans}\mathbf{}\mathbf{)}$