Compare two relationships shown in different ways

Answer Key - Grade 8 Math Worksheet

Circle the best answer, or write your answer on the line.

1. Read this first

   A (rule): y = 3x + 10. B

   table, minutes	liters
   4	21
   0	1
   2	11

2. 1.

   Bo fills two pails, A and B. B's rows are mixed up. Which pail fills faster?

   • They fill equally fast: both end near 21
   • A fills faster: it starts higher, at 10 liters
   • B fills faster: 5 liters a minute, more than 3
3. 2.

   B (rule): d = 90t. Two walkers in Esme's club, A and B, walk at steady speeds. B follows d = 90t (meters after t minutes). Who walks faster?

   • They walk equally fast: both start at 0
   • B walks faster: 90 m a minute, more than 80
   • A walks faster: 400 m each row, more than 90
   • A walks faster: its table reaches 800 m
4. 3.

   Two riders in Jun's bike club, A and B, ride at steady speeds. B follows d = 15t (km after t hours). Who rides faster?

   • They ride equally fast: both riders start at 0 km
   • A rides faster: its graph reaches 36 km
   • B rides faster: 15 km an hour, more than 12
5. 4.

   B (rule): y = x + 9. Luz compares two plants, A and B, with no row for week 0. Which plant started taller (at week 0)?

   • A started taller: its first row shows 11 cm in the table
   • B started taller: 9 cm at week 0, more than 7
   • A started taller: it grows 2 cm a week
6. 5.

   Milo compares two plants, A and B, with no row for week 0. Which plant started taller (at week 0)?

   • A started taller: it grows 4 cm a week
   • They started equally tall: both pass 9 cm
   • B started taller: 6 cm at week 0, more than 3
7. 6.

   B (story): a plant is 6 cm at week 0 and grows 1 cm each week. Noah compares two plants, A and B, with no row for week 0. Which plant started taller (at week 0)?

   • B started taller: 6 cm at week 0, more than 4
   • A started taller: it grows 2 cm a week
   • A started taller: its first row shows 10 cm

8. A (rule): y = 7x + 2. B

   table, weeks	cm
   0	8
   3	14
   6	20

9. 7.

   Pia compares A and B. How much faster does plant A grow than plant B, in cm per week?

   5
10. 8.

    Ren compares A and B. How much faster does kite A's string go out than kite B's, in meters per second?

    4
11. 9.

    B (story): a jar has 10 buttons and gets 4 more each day. Tala compares A and B. How much faster does jar A fill than jar B, in buttons per day?

    3
12. 10.

    Zee compares A and B. How much faster does pail A fill than pail B, in liters per minute?

    4