What is the probability of one of the coins landing on tails and two of them landing on heads?

How many ions that have a +1 charge will bond with an ion that has a -2 charge

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

Which are examples of how technology has advanced scientific understanding.1using hot water to sterilize medical equipment.2transplanting a human organ into another individual.3inserting genes from one sheep into another cell to make a cloneunderstanding the different structures that make up a cell.4examining microorganisms from the deepest parts of the ocean