The beta decay of cesium-137 has a half-life of 30.0 years. how many years must pass to reduce a 24 mg sample of cesium 137 to 6.0 mg?

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.