Question

An element with Mass 630 grams decays by 18.8% per minute. How much of the element is remaining after 7 minutes, to the nearest 10th of a gram?

Answer 1

$630 \times {81.2}^{7}$
1.5

Answer 2

Answer:

146.6 grams

Step-by-step explanation:

We have been given an element with Mass 630 grams decays by 18.8% per minute.

We will use exponential decay function to solve our given problem.

$y=a\cdot (1-r)^x$, where,

y = Final amount,

a = Initial amount,

r = Rate of decay in decimal form,

x = Time.

$18.8\%=\frac{18.8}{100}=0.188$

Substitute the given values:

$y=630\cdot (1-0.188)^7$

$y=630\cdot (0.812)^7$

$y=630\cdot 0.232751347$

$y=146.633349$

$y\approx 146.6$

Therefore, 146.6 grams of the element is remaining after 7 minutes.