Problem Solving with Four Operations and Rational Numbers

A biologist is studying the growth of a bacterial colony. The colony doubles in size every 3 hours. If the initial size of the colony is 500 bacteria, how many bacteria will there be after 9 hours?

• 1000

• 2000

• 4000

• 8000

A chemist is preparing a solution and needs to add 0.75 grams of solute to 250 ml of solvent. What is the concentration of the solution in grams per liter?

• 3 g/L

• 2.5 g/L

• 1.5 g/L

• 0.75 g/L

A physics experiment requires a force of 10 N to move a 2 kg object. What is the acceleration of the object?

• 5 m/s^2

• 10 m/s^2

• 2 m/s^2

• 20 m/s^2

Tags

NGSS.MS-PS2-2

A student is conducting an experiment to measure the pH of a solution. If the pH meter reads 4.5, what is the concentration of hydrogen ions in the solution?

A researcher is analyzing a sample that contains 40% water and 60% solute. If the total mass of the sample is 150 grams, what is the mass of the solute?

• 60 grams

• 90 grams

• 100 grams

• 120 grams

A physics student is calculating the work done by a force of 15 N moving an object 3 meters. What is the work done?

• 30 J

• 45 J

• 60 J

• 75 J

Tags

NGSS.HS-PS3-1

A chemical reaction requires a temperature of 300 K. If the current temperature is 273 K, how much must the temperature be increased?

• 27 K

• 37 K

• 47 K

• 57 K

Tags

NGSS.MS-PS3-4

A biologist is observing a population of rabbits that triples every month. If there are 100 rabbits initially, how many will there be after 2 months?

• 300

• 600

• 900

• 1200

A scientist is measuring the density of a liquid. If the mass of the liquid is 200 grams and the volume is 250 ml, what is the density?

• 0.8 g/ml

• 1.0 g/ml

• 1.2 g/ml

• 1.4 g/ml