Scientists found a fossilized bone from an organism at an excavation site in North Dakota. When they took the bone back to the lab, they realized that the bone had only 12.5% of the total carbon-14 left. Based on the amount of carbon-14 left in the bone how old is the bone if the half-life of carbon-14 is 5730 years? A) 5730 years old B) 17,190 years old C) 71,625 years old D) Cannot determine answer based on information given.

B. 17190 years old

Explanation:

It takes 5730 years for a particular amount of carbon-14 in the bone to reduce by halve its initial quantity. So

At the death of the animal the c-14 content was 100%, the decay steps is shown below

100% decays down to

50% in 5730 yrs.

The 50% decays down to

25% in 5730 yrs.

The 25% decays down to

12.5% in 5730 years.

This means that for 12.5% of c-14 to be left the c-14 has gone through 3 half lives which puts its age at

5730+5730+5730 = 17190 years

elly's long hair:

a. if the salon only takes cash, then this isn't the problem. it doesn't matter how much she has in her checking account.   she can't get a haircut until she has the cash.

b. if she has overdraft protection, then there's no problem.   she can go ahead and write a check that her account can't cover, then sometime later, pay the bank some outrageous usury for loaning her a few bucks for a few days, but with beautiful hair.

c. if elly has some principles, and doesn't want to write a bad check, then now she has a problem.   her desire for the new hairstyle is in conflict with her honesty and integrity.

d.   if the bank will not process a check she writes, then even if she had a million $$ in her account, she couldn't use any of it.   the amount she has in her account is not the problem.   and if i may suggest, she might as well close her checking account, and put the money where it'll work for her.   it's not doing her a bit of good in a checking account, since she can't write any checks.

justin can't pay the full balance:

a. he can't even handle the credit limit he has now.   under no circumstances should he ask for a higher limit.

b.   he can ask for the grace period to be extended.   but that's no solution, the bank will almost certainly refuse anyway, and there are much better options.   he knew the rules of his credit card when he started using it.

c.   he definitely should pay the interest on the balance, plus as much of the balance as he can cover at the same time.

d.   he definitely should pay the minimum otherwise they could shut down his card.   he should also pay as much more as he possibly can.   he should also remember the awkward situation he's in, stop buying stuff on credit that he can't afford, and avoid adding any more debt.

i'd say that justin's best best option isn't on this list of choices.   what he has to do:   pay as much as he can at least the minimum payment plus as much more as he can and then avoid adding more debt.

seeing the graph would