Answer:
0.035 kg
Explanation:
(0.07 kg / 1 litre) x (0.5 litre)
= 0.035 kg
Notice how the units of litres cancel and all you are left with is units of kg which is what we want. Another way of solving this problem is via logic. If 1 litre of water is needed for 0.07 kg salt, then half a litre of water (0.5) would need half of the amount needed by 1 litre water so (0.07/2) = 0.035 kg