Amir K. answered • 08/08/20

Teacher extraordinaire

You need to use this formula

A(t) = A_{0}e^{-kt},

k = a constant

t = minutes elapsed from the time when A was A0

The first step is to find the value of k

7.75= 17e^{-24k}

^{Take the log of both sides and arrange the equation to get:}

k = [-ln(7.75/17) / 24]

k= 0.03273 min^{-1}

^{Now using the value of k and A(t) as 2:}

2 = 17e^{-0.03273t}

and solve for t.

t = ln(2/17) / (-0.03273) min ≅ 65.38min