Doctors can use radioactive chemicals to treat some forms of cancer. the half life of a certain chemical is 5 days. a patient receives a treatment of 16 millicuries of the chemical. (a millicurie is a unit of radioactivity.) how much of the chemical remains in the patient 10 days later?

You'll need a half-life formula.  (See attached) (Use the formula at the bottom).

Ending Amount = Beginning Amount / 2 ^n
where "n" is the number of half-lives.
Half life is 5 days, so amount remaining after 10 days is
1/2^2 or 1/4 of the original is left

One shot. if 60% of 10 is 6, then what is 70%? we know it would be seven (since 60% is mathematically 60/100, or 6/10, then 70% is 70/100, or 7/10) but we can check anyway using ratios: 6 : 60% = x : 70%*inverse multiplicationx * 60% = 6 * 70%*divide both sides by 60%x = (6 * 70%) / 60%x = 7and since he has made 6 shots already, he would need just one more to get 7 shots or 70%. if the explanation is too confusing, comment and i will try to