Question

A school needs to raise at least
$
600
for a field trip. The student price is
$
4
and the adult price is
$
8
. There are
130
students attending the field trip.



Which inequality represents the number of adults,
x
, needed to raise at least the
$
600
?



A.
4
x
−
8
(
130
)
≥
600

B.
4
x
+
8
(
130
)
≥
600

C.
4
(
130
)
−
8
x
≥
600

D.
4
(
130
)
+
8
x
≥
600

Answer 1

Revenue = student revenue + adult revenue = 4(130) + 8x. It must be at least 600, so

4(130) + 8x ≥ 600.

This is choice D. (If solved: 520 + 8x ≥ 600 ⇒ 8x ≥ 80 ⇒ x ≥ 10.)