Patterns AB ABB ABC — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Red, blue, red, ___, red, blue. What color is missing?
A) blue
B) yellow
C) green
D) red
AB pattern alternates red and blue, so blue fills the missing fourth spot.
2. In the AB pattern red, blue, red, blue, what is the 8th item?
A) red
B) blue
C) yellow
D) green
AB pattern places second item on even spots, so item 8 is blue.
3. Which sequence is a broken pattern?
A) red, blue, red, blue
B) A, B, A, B, A, B
C) red, blue, red, red, blue
D) 1, 2, 1, 2, 1, 2
The third choice repeats red twice, breaking the AB rule the others all follow.
4. In the ABC pattern A, B, C, A, B, C, what letter is the 6th item?
A) A
B) B
C) X
D) C
ABC pattern places C on every third spot, so item 6 is the letter C.
Part B: Fill in the Blank
Write the correct answer on each line.
1. circle, square, circle, square, circle, square
AB pattern alternates circle and square, so square fills the fourth spot here.
2. In red, blue, blue, red, blue, blue, the 8th item is blue
ABB pattern places blue on the 8th spot since red lands on 7.
3. A, B, C, A, B, C, A, B, C
ABC pattern repeats A, B, C, so C completes the second cycle here.
4. In the AB pattern cat, dog, cat, dog, the 10th item is dog
AB pattern puts dog on even spots, so the 10th item is dog.
5. red, red, blue, red, red, blue, red, red, blue
AAB pattern places blue after every two reds, so blue follows the new pair.