First, we need to find the factor by which the number of otters is being reduced, we know that their number is decreasing by 17% each month which means that each month there are only 83% of the otters that used to be one month ago.
As you can see for each month you just have to multiply (83/100) = (0.83) and you will find the number of otters after every month. So we can write this equation:
Now we already have the formula we need to find which month there are only 2250 otters which is the halving time
We need to apply the propriety of logarithms
a. The number of otters will be 2250 in 3.72 months which is the halving time.
Now we need to find the number of otters in 3 years, but remember that we are using the formula with months which means that 3 years= 36 months. So we have to replace 36 in the formula
b. After 3 years will be between 5 and 6 otters alive.