Asubstance that is dissolved in another substance is which of the following 1) saturation 2) solubility 3) solute 4) solvent

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

The body of water found at number 4 on the map above is the

The ruiz family is exchanging euros for us dollars. the exchange rate is 1 euro equals 1.35261 usd. since the ruiz family knows that usd are stated to the nearest hundredth of a dollar, they used the conversion ratio