Series and sigma notation, and the sum of an arithmetic series

Answer Key - Grade 11 Math Worksheet

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

1. 1.

   Luz works out 3 + 8 + 13 + … + 93 on a math club card. What is the sum?

   912
2. 2.

   Noah works out -9 + (-5) + (-1) + … + 63 on a math club card. What is the sum?

   513
3. 3.

   Pia works out Σ from k = 1 to 20 of (3k + 2) on the class board. What is the sum?

   670
4. 4.

   Ren works out Σ from k = 1 to 25 of (4k − 3) on the class board. What is the sum?

   1225
5. 5.

   Zee works out Σ from k = 6 to 20 of (5k − 4) on the class board. What is the sum?

   915
6. 6.

   Ari's school hall has 16 rows. Row 1 has 20 seats, and each row has 2 more than the row before. How many seats are in the hall?

   560
7. 7.

   An outdoor theater has 18 rows. Row 1 has 24 seats, and each row has 3 more than the row before. How many seats does Jun count in all?

   891
8. 8.

   Kira writes 5 + 8 + 11 + … + 32 in sigma notation. Which one is right?

   • Σ from k = 1 to 32 of (3k + 2)
   • Σ from k = 1 to 10 of (5k + 3)
   • Σ from k = 5 to 32 of k
   • Σ from k = 1 to 10 of (3k + 2)
   • Σ from k = 1 to 9 of (3k + 2)
9. 9.

   Milo writes 9 + 11 + 13 + … + 47 in sigma notation. Which one is right?

   • Σ from k = 9 to 47 of k
   • Σ from k = 1 to 20 of (9k + 2)
   • Σ from k = 1 to 47 of (2k + 7)
   • Σ from k = 1 to 20 of (2k + 7)
   • Σ from k = 1 to 19 of (2k + 7)
10. 10.

    Noah writes 1 + 7 + 13 + … + 67 in sigma notation. Which one is right?

    • Σ from k = 1 to 11 of (6k − 5)
    • Σ from k = 1 to 12 of (k + 6)
    • Σ from k = 1 to 67 of (6k − 5)
    • Σ from k = 1 to 67 of k
    • Σ from k = 1 to 12 of (6k − 5)