Determine the amount of time it would take for an investment to double if interest is earned at a rate of 3.75% compounded continuously. Use a graph to find your answer.

Question

A. 1.85 years
B. 1.93 years
C. 18.48 years
D. 18.83 years
E. 19.80 years*
____________________________________________________________

Cobalt-60 is used for radiotherapy. It has a half-life of 5.26 years. If 4 g of cobalt-60 is administered, how much remains in 3 years?

A. 1.2 g*
B. 2.7 g
C. 3.3 g
D. 2.1 g
E. 0.2 g

Could someone kindly help me double check these answers to these questions? Thank you all so much!!!!!! :) :D 🙂☻☺😀 ツ :-)😃

Answer 1

#1. You want t where
e^(.0375t) = 2
Not E. What calculation did you use?

#2. Not A
since less than one half-life has passed, more than half of the original amount must remain. What calculation did you use?

Answer 2

So #1 is C or C., and #2 is B or B.?

Answer 3

Because I am very confident in these two new answers of mine! Hehe.

Answer 4

They both turned out to be right when I submitted my assessment or assignment! Thank you so much, oobleck, for your help!!!!!!!! :) :D 😃

Answer 5

For those wondering, the correct answers to these questions were actually 18.48 and 2.7 respectively