For this question, you will need a friend. Have this individual grab a handful of coins making sure there are only two types of coins in the group (i.e., nickels and dimes, quarters and pennies, pennies and dimes, etc). Your friend should tell you the type of coins they’ve chosen, how many coins they have and the dollar amount of the group. From this information, you will set up two sets of equations and determine how many of each coin they have in their hand.

Question

anonymous · Answer

pennies and quarters. 15 coins total.  39 cents total.

anonymous · Answer

that should be easy enough

anonymous · Answer

q + p = 15
.25q + .01p = 39

anonymous · Answer

what you're trying to figure out is how many quarters I have and how many pennies I have. So the equation should be something like, .25q + .01p

anonymous · Answer

right, now divide from both sides

anonymous · Answer

how do i do that?

anonymous · Answer

.25q+.01p=.39
/.25              /.25

you'll get 1.56. There's 1 quarter. Subtract .25 from .39.
.01p=.14
/.01    /.01

p=14

anonymous · Answer

Thanks Carissa (: