Solve the problem.
-For a culture of 70,000 bacteria of a certain strain, the number of bacteria $\mathrm { N }$ that will survive $x$ hours is modeled by the formula $N = 7000 \sqrt { 100 - x }$. After how many hours will 63,000 bacteria survive?
A) $81 \mathrm { hr }$
B) $37 \mathrm { hr }$
C) $19 \mathrm { hr }$
D) $91 \mathrm { hr }$

Question

Quizplus · Accepted Answer

To find the number of hours after which 63,000 bacteria will survive, we set $N = 63000$ and solve for $x$ in the given formula: $63000 = 7000 \sqrt { 100 - x }$. Dividing both sides by 7000 gives $9 = \sqrt { 100 - x }$. Squaring both sides results in $81 = 100 - x$, which leads to $x = 19$ hours.

Solve the Problem N\mathrm { N }N That Will Survive xxx Hours Is Modeled by the Formula

Solve the Problem $\mathrm { N }$ That Will Survive $x$ Hours Is Modeled by the Formula