Hey guys, please i need the maths gurus in the house to help out with this problem, i know it is the simplest of all, but my head too rust to even think right now. infact there are two questions so enjoy!!!

1. Let's say you run a small retail shop in a shopping mall and you are considering whether or not you will stay open on a Saturday morning. You know that a customer on entering the store it likely to make a purchase of $10.00 or more 35% of the time. The remainder of the time they will look around and leave without making a purchase. Your shop draws about 15% of total shoppers on any given day. You also expect from information that you have gathered from mall sources that there are about 500 people in the mall on a Saturday morning. You know you need to have about $300.00 in revenue to cover expenses and profit for a half day on Saturday morning and the question is should you open the shop? ( What is the probability that at least 30 shoppers entering your store of the total will make a purchase of $10.00 or more?)

2.
Let's ask a binomial question, folks. Let's say that you have flipped a coin 25 times and the results are Heads 15, Tails 10. What is the probability of obtaining a Tail on the next flip of the coin? That's one, now to what characteristics are present in a binomial process that ensures this result?

thanks guys.