SOLUTION: 3. An investor bought 500 shares of stock , some at $ 3.50 per share and some at $6.00 per share. If the total cost was $ 2187.50, how many shares of each stock did the investor bu

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Question 139510: 3. An investor bought 500 shares of stock , some at $ 3.50 per share and some at $6.00 per share. If the total cost was $ 2187.50, how many shares of each stock did the investor buy?
(a) How will you set up the problem?
(b) What is the equation in terms of the variables?
(c) Which shares are more?

Found 2 solutions by stanbon, frostusna:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
An investor bought 500 shares of stock , some at $ 3.50 per share and some at $6.00 per share. If the total cost was $ 2187.50, how many shares of each stock did the investor buy?
(a) How will you set up the problem?
Let # of 3.50 shares be "x" ; value is 3.5x dollars
# of 6.00 shares is "500-x" ; value is 6(500-x)=3000-6x dollars
EQUATION:
value = value = 2187.50
3.5x + 3000-6x = 2187.5
-2.5x = -812.5
x = 325 (# of 3.50 shares)
500-x = 175 (# of 6.00 shares)
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(b) What is the equation in terms of the variables?
(c) Which shares are more?
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Cheers,
Stan H.

Answer by frostusna(7) (Show Source):
You can put this solution on YOUR website!
You have two unknowns, the number of each stock bought, so you need two equations.
First, let x=number of stock at $3.50 and y=number of stock at $6.00.
We know that
and we know
Solve the first equation for y: and substitute this value for y into the second equation.

the number of $3.50 stocks bought.
the number of $6.00 stocks bought.