7.4B HW Answers
2. Jose has $2.45 in nickels and dimes. He has
ten more nickels than dimes. How many of
each does he have?
0.05n + 0.10d = 2.45
5n + 10d = 245
n = d + 10 = 13 + 10 = 25
5(d + 10) + 10d = 245
5d + 50 + 10d = 245
15d + 50 = 245
15d = 195
d = 13
3. A jar filled with only dimes and quarters
contains a total of 59 coins. The value of all
the coins in the jar is $9.65. How many
quarters are in the jar?
0.10d + 0.25q = 9.65
(–10)
d + q = 59
10d + 25q = 965
+
-10d–10q = -590
15q = 375
q = 25
4. Ernie has $3.65 in nickels and dimes. He has
13 more nickels than dimes. How many of
each coin does he have?
0.05n + 0.10d = 3.65
5n + 10d = 365
n = d + 13 = 20 + 13 = 33
5(d + 13) + 10d = 365
5d + 65 + 10d = 365
15d + 65 = 365
15d = 300
d = 20
5. A jar filled with only nickels and quarters
contains a total of 65 coins. The value of all
the coins in the jar is $9.65. How many
quarters are in the jar?
0.05n + 0.25q = 9.65
(–5)
n + q = 65
+
5n + 25q = 965
-5n – 5q = -325
20q = 640
q = 32
6. Tickets to a local movie were sold at $6.00 for
adults and $4.50 for students. If 210 tickets
were sold for a total of $1,065, how many
student tickets were sold?
6a + 4.50s = 1065
(–600)a + s = 210
600a + 450s = 106500
+-600a–600s = -126000
-150s = -19500
s = 130
7. Tickets to a play were sold for $25 for adults
and $15 for children. If 441 tickets were sold
for a total of $8415, how many children tickets
were sold?
25a + 15c = 8415
(–25) a + c = 441
25a + 15c = 8415
+
-25a –25c = -11025
-10c = -2610
c = 261
8. The Steele Canyon ASB sold advance tickets
to the dance for $4 per ticket. Anyone who
attended and purchased their ticket at the
door had to pay $5 a ticket. A total of 480
students attended the dance and ASB earned
$2100. How many students bought tickets at
the door?
4a + 5d = 2100
(–4) a + d = 480
+
4a + 5d = 2100
-4a – 4d = -1920
d = 180
9. Altogether 292 tickets were sold for a high
school basketball game. An adult ticket costs
$3 and a student ticket costs $1. Ticket sales
were $470. How many of each type of ticket
were sold?
3a + 1s = 470
(–1) a + s = 292
89 + s = 292
s = 203
+
3a + s = 470
-a – s = -292
2a = 178
a = 89