SOLUTION: Can someone help me please? I'm having a real hard time with this. A student makes a $9.50 purchase at the bookstore with a 20 dollar bill. The store has no bills and gives the ch

Question 191743: Can someone help me please? I'm having a real hard time with this.
A student makes a $9.50 purchase at the bookstore with a 20 dollar bill. The store has no bills and gives the change in quarters and 50-cent pieces. There are 30 coins in all.How many of each kind are there? Thanks alot.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A student makes a $9.50 purchase at the bookstore with a 20 dollar bill. The store has no bills and gives the change in quarters and 50-cent pieces. There are 30 coins in all.How many of each kind are there?
----------------
Change = $10.50
------------------
Equations:
Quantity Eq.::: q + f = 30
Value Eq;;;;;;25q + 50f = 1050 cents
---------------------------------------------
Solve by substitution:
q = 30-f
Substitute to get: 25(30-f) + 50f = 1050
750 - 25f+ 50f = 1050
25f = 300
f = 12 (# of 50-cent pieces)
-----------------------
Substitute into q + f = 30 to solve for "q":
q + 12 = 30
q = 18 (# of quarters in the change)
================================================
Cheers,
Stan H.

RELATED QUESTIONS
I am confused by this, can someone please help? A student makes a $10.50 purchase (answered by josgarithmetic)

I'm having a hard enough time in Algebra - now they want me to deal with "imaginary"... (answered by ptaylor)

I am brain dead today and could use help here please! Thanks so much for any help you can (answered by scott8148)

I am having a hard time with this problem...can someone please help me out. I am not... (answered by stanbon)

I am having a hard time with my homework can someone please help me thank you. if... (answered by navytutor)

I am having a hard time with a question on Exponents and roots. My question is this... (answered by longjonsilver)

Multply: (b+1/3)(b+1/4) I am having a hard time with fractions. Can someone help me... (answered by mathispowerful)

Solve the equation by completing the square: x^2 + 8x = 14 can someone help me please... (answered by josmiceli)

I am having a hard time with this, can someone help me please? Rewrite the middle term (answered by stanbon)