Answer:
90
Step-by-step explanation:
Quarters , q = 25 cent
Nickel, n = 5 cent
3 times as many nickels as quarters;
n = 3q
Total value of coins = $12
n + q = $12
0.05n + 0.25q = 12
0.05(3q) + 0.25q = 12
0.15q + 0.25q = 12
0.40q = 12
q = 12 / 0.40
q = 30
n = 3q
n = 3(30)
n = 90
90 nickels