Question

Suppose $3kg$ of sugar contains $9\times {10}^6$ crystals. how many sugar crystals are there in
a) $5kg$ of sugar?
b) $3.5kg$ of sugar?

Answer 1

$3kg$ of sugar contains $9\times {10}^6$ crystals

$\Rightarrow 1kg$ of sugar contains $\frac{9\times {10}^6}{3}$ crystals

$\Rightarrow 5kg$ of sugar contains $3\times {10}^6\times 5=15\times {10}^6$ crystals

$\Rightarrow 3.5kg$ of sugar contains $3\times {10}^6\times 3.5=10.5\times {10}^6$ crystals