Question

Gunpowder contains 75% nitre and 10% sulphur. Find the amount of the gunpowder which carries 9 kg nitre. What amount of gunpowder would contain 2.3 kg sulphur?

 

Answer 1

Let the amount of gunpowder that contains 9 kg nitre be x kg. 
\[i . e . , \frac{75}{100} \times x = 9\]
\[ \Rightarrow \frac{100}{75} = \frac{x}{9}\]
\[ \Rightarrow x = \frac{900}{75}\]
\[ \Rightarrow x = 12\]
∴ The amount of gunpowder containing 9 kg nitre is 12 kg.
Let the amount of gunpowder containing 2 . 3 kg sulphur be y kg.
\[ i . e . , \frac{10}{100} \times y = 2 . 3\]
\[ \Rightarrow \frac{100}{10} = \frac{y}{2 . 3}\]
\[ \Rightarrow y = \frac{230}{10}\]
\[ \Rightarrow y = 23\]
∴ The amount of gunpowder containing 2 . 3 kg sulphur is 23 kg.