Describe a controlled experiment on if ants like honey or butter

There are many types of techniques to control and avoid confounds in an experiment:

1. Elimination

2. Constancy of conditions

3. Balancing

Marcia dissolved 1 kg of salt in 3 litres of water.

Bobby dissolves 2 pounds of salt in 7 pints of water

2.11 pints = 1 litre

7 pints = 7/2.11

= 3.32 litre

1 pound = 0.45 kg

2 pound = o. 45*2 kg

= 0.9 kg

So we find that Bobby is dissolving 0.9kg of salt in 3.32 litre of water

Marcia is dissolving 1 kg of salt in 3 litres of water.

So it can be said that Marcia made a more concentrated salt solution.