Your patient IV bag holds 1000 ml of normal saline. An hour later, you see that 750ml is left. What percentage of the saline has been infused? What percent do you expect to be remaining two hours after that?

25% has been used in an hour. 2 hours later, it will be at 25%

Step-by-step explanation:

if 1000ml is the starting amount, and we know that 250ml is subtracted every hour, then we know that in 2 hours, 500ml will be infused, leaving 250ml (25%) saline left.

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.