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# 7.Suppose 2 kg of sugar contains $$9 \times 10^6$$ crystals. How many sugar crystals are there in (i) 5 kg of sugar? (ii) 1.2 kg of sugar?

Given: we have 2 kgs of sugar containing $$9 \times 10^6$$ crystals.So let x and y crystals are in 5 kg of sugar and 1.2 kg of sugar.
(i)We can see that this is the case of direct proportion,So we have

$$\frac{9\times 10^6}{2}=\frac{x}{5}$$

$$\Rightarrow x= \frac{5\times 9 \times 10^6}{2}$$

$$\Rightarrow x= \frac{ 9 \times 10^7}{4}$$

$$\Rightarrow x=2.25\times 10^7$$

Hence, for 5kg of sugar we have $$2.25\times 10^7$$ crystals.

(ii) $$\frac{9\times 10^6}{2}=\frac{y}{1.2}$$

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

$$\Rightarrow x=0.6\times9\times 10^6=5.4\times 10^6$$

Hence, for 1.2kg of sugar, we have $$5.4\times 10^6$$ crystals.