Nickels = x
dimes = x + 4
quarters = x
Value of coins:
nickel = 5 cents
dime = 10 cents
quarter = 25 cents
5x + 10(x + 4) + 25x = 3.20
5x + 10x + 40 + 25x = 320
40x = 320 - 40
40x = 280
x = 280/40
x = 7
There are 7 quarters, 7 nickels and 11 dimes.
Fractions and decimals are related in a very close way. Ways such as they are both representing a whole number.
for example
1/2 , 0.5 , 50%
all three numbers have the same value but are expressed in a different format. all three represent the same whole number.
another example would be
1/4 , 0.25 , 25%
hopefully this helped. and or makes sense.
LET ME KNOW :p
Answer
Find out the ratio of price to pound for each bag.
To prove
As given
A store sells grass seed in small bags and large bags.the small bags have 7 pounds of seed for $27.93 .
7 pound = $27.93
Now find out the cost for the 1 pound.

1 pound cost = $3.99
As given large bags cost $66.98.
Now find out pounds in the large bags.
Let us assume that the number of pounds in the large bags be x.
Than
3.99 × x = 66.98

x = 16.8 pounds (approx)
Now find out the ratio of price to pound for each bag.
As small bags weight = 7 pounds
Cost of the small bags = $27.93

As large bags weight = 16.8 pounds
Cost of the large bags = $66.98

Hence proved