Answer:
21 quarters, 6 dimes, and 11 nickels
Step-by-step explanation:
# of Quarters = x.
# of Dimes = y.
# of Nickels = z.
(i)x = 3y+3.
(ii) 0.25x + 0.1y + 0.05z = 6.4
(iii) x + y + z = 38.
Multiplying (iii) by -0.05, and adding it to (ii),
we then get:
0.2x + 0.05y = 4.5.
Now plug in (i) into this.
0.65y + 0.6 = 4.5.
0.65y = 3.9
y = 6.
Since y = 6, we can subsitute this into our equation.
0.2x + 0.3 = 4.5
0.2x = 4.2
x = 21.
Since x = 21, y =6, then z = 11.
