24. a radioactive substance decays exponentially. a scientist begins with 110 milligrams
of a radioactive substance. after 31 hours, 55 mg of the substance remains. how
many milligrams will remain after 42 hours?

d. corresponding side lengths in similar triangles are proportional in length.

step-by-step explanation:

yes, gavin is right.

step-by-step explanation:

gavin is correct. 

this problem is about converting 9% per year to how many percent per quarter. the rate is still the same. it only differed in the time period. so, through dimensional analysis,

9% per year  × (1 year / 4 quarters) = 2.25% per quarter

if he was asked to convert 9% per year to how many percent per quarter  compounded quarterly, then you will not simply divide by four. this is because compounding is not linear.

hope this , have a good day. c;