18. The circumference of a circle with radius 7 cm is …
a. 14 cm
b. 21 cm
c. 28 cm
d. 42 cm
Answer: c. 44 cm
19. The sum of interior angles in a hexagon is …
a. 180 degrees
b. 360 degrees
c. 540 degrees
d. 720 degrees
Answer: c. 720 degrees
20. If A = {1, 2, 3, 4} and B = {3, 4, 5, 6}, then A ∩ B is …
a. {1, 2}
b. {3, 4}
c. {5, 6}
d. {3, 4}
Answer: d. {3, 4}
