Question

Suppose 2 kg of sugar contains $9\times {10}^6$ crystals. How many sugar crystals are there in 1.2 kg of sugar?

Answer 1

Let the number of sugar crystals in 1.2 kg of sugar be be x.

$\begin{array}{ccc}Weightofsugar\left(inkg\right)& 2& 1.2\\ No.ofcrystals& 9\times {10}^6& x\end{array}$

Here weight of sugar and number of crystals are in direct proportion.

$\therefore \frac{2}{9\times {10}^6}=\frac{1.2}{x}\Rightarrow x\times 2=1.2\times 9\times {10}^6\Rightarrow x=\frac{1.2\times 9\times {10}^6}{2}=0.6\times 9\times {10}^6=5.4\times {10}^6$

Hence, the number of sugar crystals are $5.4\times {10}^6$