A student is provided with 500 mL of 600 ppm solutions of fructose. What volume of this solution in millilitres contains 0.15 fructose?
Assuming it's $0.15gm$ of fructose,$$ppm=\frac{Weight\;of\;solute_{(in\;gm)}}{Weight\;of\;solution_{(in\;gm)}}10^6$$
Since density of water is $1gm/ml$, $500ml$ of water would weigh $500gm$
$$\therefore600=\frac{W_b}{500}10^6$$
$$\therefore W_b=0.3gm$$

Thus, $500ml$ of water contains $0.3gm$ of fructose. You can find out what volume will contain $0.15gm$ of it.