A scientist is measuring the amount of radioactive material in an unknown substance. When he begins measuring, there are 12.8 grams of radioactive substance. 9 days later, there are 7.33 grams. After 14 days, there are 5.38 grams. After 30 days, there are 2.00 grams. Assuming that the decay is exponential, find the equation that determines the number of grams remaining after x days and use the equation to determine the amount of radioactive material remaining after 50 days.
A. 0.56 g
B. 0.58 g
C. 3.27 g
D. 3.33 g

Question

A scientist is measuring the amount of radioactive material in an unknown substance. When he begins measuring, there are 12.8 grams of radioactive substance. 9 days later, there are 7.33 grams. After 14 days, there are 5.38 grams. After 30 days, there are 2.00 grams. Assuming that the decay is exponential, find the equation that determines the number of grams remaining after x days and use the equation to determine the amount of radioactive material remaining after 50 days.
	A.	0.56 g
	B.	0.58 g
	C.	3.27 g
	D.	3.33 g

anonymous · Answer

@shamil98  @Luigi0210

anonymous · Answer

medal will be rewarded! really neeed help, and how to do this

anonymous · Answer

do you have graphing calc?

anonymous · Answer

no:/

anonymous · Answer

Dx its a lot easier with umm i'll see how i can explain without one Dx

anonymous · Answer

okay btw, is A correct, because when I had this question last time, someone said the answer was A,  ut i still wanna know how to do it:)

anonymous · Answer

I got B

anonymous · Answer

when you graph it and everything and find the value of x you would get .58013882

anonymous · Answer

oh okay:) are you like 100% sure u think its b?

anonymous · Answer

Dx I have graph and everything and it says the # at B ... unless i put #'s wrong bu other then i am 100% sure xD

anonymous · Answer

okay awesome! thanks

anonymous · Answer

no prob.