Answer: 28 feet.
Step-by-step explanation:
Given: During the winter months, freshwater fish sense the water getting colder and swim to the bottom of lakes and rivers to find warmer water.
The total depth of the lake = 32 feet
Since, fish swims 7/8 of the depth, then the depth of lake to which the fish swim=
Since, 
therefore, 
Hence, the fish swim 28 feet in lake.
All you have to do is multiply both
Let x represent amount invested in the higher-yielding account.
We have been given that a man puts twice as much in the lower-yielding account because it is less risky. So amount invested in the lower-yielding account would be
.
We are also told that his annual interest is $6600 dollars. We know that annual interest for one year will be principal amount times interest rate.
, where,
I = Amount of interest,
P = Principal amount,
r = Annual interest rate in decimal form,
t = Time in years.
We are told that interest rates are 6% and 10%.


Amount of interest earned from lower-yielding account:
.
Amount of interest earned from higher-yielding account:
.

Let us solve for x.



Therefore, the man invested $30,000 at 10%.
Amount invested in the lower-yielding account would be
.
Therefore, the man invested $60,000 at 6%.
There are two equations and two variables. You can solve for each variable using either the elimination method or the substitution method. Here, I believe the elimination method would be best:
5a = -4b + 5
3a = -2b + 3
You can multiply the second equation by two, so the 4b and -4b in both equations will cancel each other out when you add them. So:
5a = -4b +5
6a = 4b +6
Add both equations together.
11a = 11
a = 1
Plug in the a value into any of the previous equations:
5(1) = -4b + 5
-4b = 0
b = 0
So, since we know that b = 0, 6b is also 0.