PLZ HELP!! Hot air is less dense than cool air, so hot air will rise above cool air. Increasing the air temperature inside a hot air balloon makes it lighter than the surrounding air, so the balloon can lift up. The density of hot air is about 0.25 kg per cubic meter less than that of cool air, which means a cubic meter of hot air can lift about 0.25 kg. What is the minimum volume of hot air (in cubic meters)
needed to lift a hot air balloon, which weighs 375 kg and is carrying 3 people who weigh at least 68 kilograms each? Enter the number only.

You are a clerk at convenience store. a customer owes 11.69 for a bag of potatoes chips. she gives you a five dollar bill. how much change should the customer receive?

If you eat 4 medium strawberries, you get 48% of your daily recommenced amount of vitamin c. what fraction of your daily amount of vitamin c do you still need?

The biologist has a second culture to examine. she knows that the population of the culture doubles every 15 minutes. after 1 hour and 15 minutes, her assistant found that 80,000 bacteria were present. a) what was the size of the initial population? b) predict the size of the culture at t=3 hours. what was the size of the population at 40 minutes? explain and justify your answers. c) create a graph of the population as a function of time. find an equation that can be used to predict the size of the population at any time t. d) examine the rate at which the bacteria culture is growing. how fast is the culture growing after 1 hour? after 1.5 hours? after 2 hours? use a time interval of h = 0.01 hours to estimate these rates. interpret these rates in terms of the context of the problem situation. how do these three rates compare?