Rhonda has $1.90 in nickels and dimes. The number of dimes is one less than twice the number of nickels. How many nickels does she have?

Answer 1

8 nickels

D = 2N - 1 with D = number of dimes and N = number of nickels

5N + 10D = 190

each nickel is worth 5 cents, each dime worth 10 cents. totaling 190 cents or $1.90

5N + 10(2N-1) = 190

5N + 20N -10 = 190

25N = 190 + 10

25N = 200

N = 200/25 = 8 nickels

D = 2N-1 = 2(8)-1 = 15 dimes

5(8) + 10(15) = 40 + 150 = 190