N=number of nickles
d=number of dimes
n is 2 times d
n=2d
total money is 1.20
convert to cens
120 cetns
5n+10d=120
n=2d
5(2d)+10d=120
10d+10d=120
20d=120
divide both sides by 120
d=6
6 dimes is answer
answer is A, 6 dimes
<span> It would depend on the number of rows?
This is an arithmetic sequence and the sum of n terms is -->
n/2(2a+(n-1)d), where a is the first term and d is the common
difference. In this case a = 10, d =6
n/2(20+6(n-1)) = 3n^2 + 7n = ANSWER
n = number of rows
</span>
100 by 65 = 330 perimeter = 6,500 area
90 by 75 = 330 perimeter = 6,750 area
