Question

In a change jar, Tom has nickels and dimes. The number of nickels is two times the number of dimes and the total amount of money in the jar is $1.20. How many dimes are in the jar?

Answer 1

.05n + .10d = 1.20
n = 2d

now sub 2d in for n in the first equation
.05(2d) + .10d = 1.20
0.1d + .10d = 1.20
0.2d = 1.20
d = 1.20/0.2
d = 6

n = 2d
n = 2(6)
n = 12

check..
.05n + .10d = 1.20
.05(12) + .10(6) = 1.20
.60 + .60 = 1.20
1.20 = 1.20 (correct)

there is 6 dimes and 12 nickels

Answer 2

omg thank you so much