A commuter has $345 in his commuter savings account. This account changes by -$15 each week he buys a ticket. In one time period, the account changed by -$240.
a. For how many weeks did the commuter buy tickets?

b. How much must he add to his account if he wants to have 20 weeks’ worth of tickets in his account?

Anewborn baby had about 26,000,000,000 cells. an adult has about 4.94 times 10 to the 13 power cells. how many times as many cells does an adult have than a newborn

To determine the number of deer in a forest a forest ranger tags 280 and releases them back

Finally, the arena decides to offer advertising space on the jerseys of the arena’s own amateur volley ball team. the arena wants the probability of being shortlisted to be 0.14. what is this as a percentage and a fraction? what is the probability of not being shortlisted? give your answer as a decimal. those shortlisted are entered into a final game of chance. there are six balls in a bag (2 blue balls, 2 green balls and 2 golden balls). to win, a company needs to take out two golden balls. the first ball is not replaced. what is the probability of any company winning advertising space on their volley ball team jerseys?