167k views
2 votes
An element with a mass of 990 grams decays by 16.9% per minute. To the nearest

minute, how long will it be until there are 80 grams of the element remaining?

User Skarface
by
6.1k points

2 Answers

2 votes

Answer:

14

Explanation:

User Tal Pressman
by
4.9k points
2 votes

Answer:

It will take 13.58 minutes until there are 80 grams of the element remaining

Explanation:

An element with a mass of 990 grams decays by 16.9% per minute.

We are supposed to find how long will it be until there are 80 grams of the element remaining

Formula :
N(t)=N_0(1-r)^t

N(t)=Amount after t minutes


N_0=Initial amount

r = rate of decrease = 0.169

t = time in minutes

Substitute the values in the formula :


80=990(1-0.169)^t


(80)/(990)=0.831^t

t=13.58

Hence It will take 13.58 minutes until there are 80 grams of the element remaining

User Zuu
by
5.2k points