An inequality can be formed by simply translating the problem statement to numerical expressions.
From the problem we know that

added with

hours should be equal or greater than

(helpful insight from the keyword "at least"). Therefore, it's inequality would look like:

(>= is used instead of ≥ for constraints in formatting)
The inequality above best models the situation.
Answer:
6 days
Step-by-step explanation:
pay 60 = -60
Let d = the number of days
30d - 60 = sister
20d = me
Equation:
30d - 60 = 20d Move 30 to the other side
-30d -30d
-60 = 20d - 30d Combine liked terms
-60 = -10d
-10 -10 Divide
d = 6
Answer:
15.63 cm^3
Step-by-step explanation:
Assuming that the ice cube is a perfect cube, then all of the sides are equal. There for, each side is 2.5 cm.
v = l*w*h
v = 2.5 * 2.5 * 2.5
v = 6.25 * 2.5
v = 15.625 cm^3
1/3 hour = 20 minutes
1 1/2 dozen = 12 + 6 = 18 cookies
18 cookies x 3 (3 sets of 20 minutes = 1 hour) = 54 cookies per hour