We can use the compound interest formula
F=P(1+i)^n
where
F=Future value of investment to be found
P=present value of investment ($1000)
i=interest per period (1/4 year)=0.04/4=0.01
n=number of periods (3 years * 4 quarters = 12)
Substitute or "Plug in" values, so to speak,
F=1000*(1+0.01)^12
use a calculator to do the sum
=1126.83 (to the nearest cent, and use the proper rounding rules)
3 1/8
First you take the all the dogs that gained 3/4 (which is 4)
Then you multiply it by 4
3/4x4=3
Then you add the dogs that gained 1/8 of a pound
3+1/8=3 1/8
15% of 20 gal = 0.15 * 20 gal = 3 gal, so the solution contains 3 gal of salt.
If we add <em>x</em> gal of water to the solution, we end up with (20 + <em>x</em>) gal of solution. We want the new mixture to have a concentration of 10%, or
10% of (20 + <em>x</em>) gal = 0.1 * (20 + <em>x</em>) gal = 2 + 0.1<em>x</em> gal
of salt.
The amount of salt in the tank hasn't changed. Solve for <em>x </em>:
2 + 0.1<em>x</em> = 3
0.1<em>x</em> = 1
<em>x</em> = 10 gal
The next two term in patterns is below
3,6,5,10,9,18,17,34,33,66