i have 50 coins in quarters and nickels. if the total value is $5.90, how many of each coin do i have ?

2 answers

start out with what you know
-so you have a total of 50 coins
-a quarter is equal to 25c
-a nickel is eqal to 5c

0.25*4=$1.00
0.25*12=$3.00
0.25*16=$4.00
0.25*20=$5.00

0.05*20=$1.00

20+16=36 50-36=14

This might help
You know you have at least 3 nickels, because only $5.75 can be made with just quarters. So, you have at most 47 quarters.

47 quarters = $11.75
plus 3 nickels = $11.90

That is $6.00 too much.
Each quarter replaced by a nickel reduces the value by 20 cents.

Since you have $6.00 too much, replace 30 quarters with nickels. That leaves

17 quarters + 33 nickels.
$4.25 + $1.65 = $5.90