Which statements include two quantities in the real world that are additive inverses? Select each correct answer.

A plane ascends 500 yards and descends 100 yards.

A driver drives 40 miles north and 30 miles south.

A person deposits $100 in to her bank account and then withdraws $100 from the same account.

Twenty gallons of water leak from a pool and 20 gallons are put back into the pool.

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?