Question 201950
This is a common type of problem. 
I like this process to solve these.
lemon drops are to be mixed with jelly beans to make 100 lbs of mixture. How many pounds of each candy should be used?
lemon drops/ $1.90 lb.     jelly beans/ $1.20 lb.      mixture/ $1.48 lb
Let the number of pounds of lemon drops be represented by l
Let the number of pounds of jellybeans be represented by j
You are told the number of pounds in the mixture {{{l + j = 100}}}. This is one equation
You are told the price/pound of lemon drops, jelly beans and mixture.
So you can setup a second equation
{{{l*1.90 + j*1,20 = 100*1.48}}}
{{{1.9l + 1.2j = 148}}}
{{{   l +    j = 100}}}   

Let's use elimination to solve
{{{1.9l + 1.2j = 148}}}
{{{1.9l + 1.9j = 190}}}  This is our first equation times 1.9. Now subtract
-----------------------
{{{ -0.7j = - 42}}}
{{{ j = 42/.7 = 60}}}
{{{l + j = 100}}}
{{{l = 100 - j}}}
{{{l = 40}}}
Check you answer
Does {{{1.9*40 + 60*1.2 = 148}}}???