Question 832557
Both of these may be considered mixture problems.


The investment question:


Target income is 5000 dollars.

{{{20000*0.08+x*0.07=5000}}}, looking at the sum of the interests for a year.
{{{0.07x=5000-20000*0.08}}}
{{{x=(1/0.07)(1000)(5-20*0.08)}}}
{{{x=(1000)(3.4)/0.07=3400/0.07=340000/7}}}
{{{x=48571}}} dollars



The cream fat blending question:


"Mixing two concentrations for known amount of mixture"
----Find this lesson in my profile's lessons link.
{{{2*u+22*v=4*20}}} and {{{u+v=20}}}