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. 1.

   B (rule): y = 6x + 2. Ari measures two sunflowers, A and B. A is in a table every 2 weeks. Which sunflower grows faster?

   • A grows faster: it jumps 8 cm each row, more than 6
   • B grows faster: 6 cm a week, more than 4
   • They grow equally fast: both are sunflowers

2. Read this first

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

   table, minutes	liters
   4	21
   0	1
   2	11

3. 2.

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

   • B fills faster: 5 liters a minute, more than 3
   • They fill equally fast: both end near 21
   • A fills faster: it starts higher, at 10 liters
4. 3.

   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?

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

5. A (story): a 30 cm candle burns 2 cm each hour. B

   table, hours	cm
   0	24
   2	18
   4	12

6. 4.

   Kira lights two candles, A and B. Which candle burns down faster?

   • They burn equally fast: both are candles
   • B burns faster: 3 cm an hour, more than 2
   • A burns faster: it starts taller, at 30 cm
7. 5.

   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: it grows 2 cm a week
   • B started taller: 9 cm at week 0, more than 7
   • A started taller: its first row shows 11 cm in the table
8. 6.

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

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

   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)?

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

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

    table, weeks	cm
    0	8
    3	14
    6	20

11. 8.

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

    5
12. 9.

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

    4
13. 10.

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

    4