Answer:
20x25=500 10x25+10×25=500
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.