737x79 using estimating I really need halp

Initially 100 milligrams of a radioactive substance was present. after 6 hours the mass had decreased by 4%. if the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (round your answer to one decimal place.)

What is the distance between (–2 1/2,-3) and (1, –3)?

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)