A car radiator has a 16-quart capacity and is currently filled with a 40% antifreeze solution. How many quarts of this solution should be drained off and replaced with 100% antifreeze so that the radiator is filled with a 50% antifreeze solution? express your answer as a common fraction.

Which statements are true for invasive species? 1. they always stabilize an ecosystem. 2. they’re always successful in adjusting to a new habitat. 3. they often compete with the native species for resources. 4. they have the ability to displace the native species. 5. they’re always pests.