Constant Rate Word Problems

T-mobile charges a base rate of $30 per month for unlimited text plus $.10/ minute of talk time. Write the function for monthly cost for x minutes. ​ (a)   what is the independent variable ​ (b)   what is the dependent variable ​ (c)  

• f(x)=20 + .10x

• f(x)= .10 + 30x

• f(x)= 30x + $.10x

• f(x)=30+ $.10x

• minutes

• cost

Find the rate of change. (TRICKY)

• 2

• Its not constant

• 1

• 1/2 or .5

Working alone, it takes Stephanie seven hours to clean an attic. Shayna can clean the same attic in 12 hours. Find how long it would take them if they worked together.

• 4.42 hours

• 4 hours

• 3.24 hours

• 3 hours

Sally and Dan were able to paint a room in 3 hours together. It takes Dan 4 hours to do this job alone. Without help, how long would it take Sally to do this job ?

• 11 hous

• 12.54 hours

• 12 hours

• 13 hours

It takes Darryl nine hours to mop a warehouse. Castel can mop the same warehouse in eight hours. Find how long it would take them if they worked together.

• 3.12 hours

• 4 hours

• 4.13 hours

• 4.24 hours

Working alone, Shanice can tar a roof in 12 hours. One day her friend Kathryn helped her and it only took 5.14 hours. How long would it take Kathryn to do it alone?

• 8 hours

• 8.13 hours

• 8.50 hours

• 8.99 hours

Nicole can pick forty bushels of apples in 15 hours. Carlos can pick the same amount in 11 hours. How long would it take them if they worked together?

• 6.35 hours

• 6.17 hours

• 6.09 hours

• 6 hours

Working together, Arjun and Maria can oil the lanes in a bowling alley in 4.24 hours. Had she done it alone it would have taken Maria eight hours. How long would it take Arjun to do it alone?

• 9 hours

• 9.02 hours

• 9.42 hours

• 10 hours

The amusement park charges $20 to get in plus $1.50 per ride. Which linear equation below represents this relationship.

• y=1.5+20x

• y=1.5x + 20

• y = 20x + 1.5

• y= 21.5x

The total cost (y) at an amusement park can be modeled by y=1.5x+20 where x is the number of rides you ride. What is the entrance fee?

• 1.5

• 200

• 0

• 20