Answer with explanation:
Total number of people who are going to zoo are:14.
( since mom+his son+his son's 12 friends=14 people)
now price of one ticket=$ 11.
this implies that the cost of 14 tickets=11×14=$ 154.
Hence, the remaining balance left in the credit card will be:
Available balance-Cost of all tickets.
=Available balance-$ 154.
Hence, the impact it will have on the available credit left on her credit card is that her balance will decrease by $ 154.