Answer:
9,942 bacteria were there at 10 hours.
Step-by-step explanation:
Equation for population decay:
The equation for population decay, after t hours, is given by:

In which P(0) is the initial population and r is the decay rate, as a decimal.
Researchers recorded that a certain bacteria population declined from 200,000 to 900 in 18 hours.
This means that
and that when
. So we use this to find r.



![\sqrt[18]{(1-r)^{18}} = \sqrt[18]{\frac{900}{200000}}](https://tex.z-dn.net/?f=%5Csqrt%5B18%5D%7B%281-r%29%5E%7B18%7D%7D%20%3D%20%5Csqrt%5B18%5D%7B%5Cfrac%7B900%7D%7B200000%7D%7D)


So


At this rate of decay, how many bacteria was there at 10 hours?
This is P(10). So

Rounding to the nearest whole number:
9,942 bacteria were there at 10 hours.
Answer: answer is 19.2
a squared + b squared = c2
81 + 289 = 370
square root of 370 = 19.235
answer is 19.2
AZ^2= 2^2 + 2^2 = 8
AP^2 = ZP^2 = 5^2 + 7^2 = 74
P^2of APZ = /8 + 74*2 =156
P= 12.489
A quarter is 4 pieces.
So its 8÷4=2
Hence, a quarter of 8 is 2.