1 | Page
CR-21 Landscapes and Irrigation AZROC
Test Prep Questions and Correct Answers
What is the minimum thickness of brick for the exterior wall of a
fireplace?
a) 6 inches
b) 8 inches
c) 10 inches
d) 9 inches Ans: 8 Inches
What is 1/2 inch of accumulated organic material in a grassy area
called?
a) mulch
b) ground cover
c) stolons
d) thatch layer Ans: Thatch Layer
© 2025 All rights reserved
, 2 | Page
What should be provided as a cover for the drain tile before
installing the pond liner where subdrain is used?
a) 4 inches of pea gravel
b) screen with 1/4 inch mesh
c) a pool grate
d) 8 inches of medium sized rock Ans: 4 inches of pea gravel
How do you properly plant ground cover?
a) in a circular pattern
b) in rows, each row staggered
c) in groups of 2
d) 18 inches apart in rows Ans: In rows, each row staggered
You are going to pour a concrete pad that is 16 feet by 22 feet and
4 inches thick, how many cubic yards of concrete are needed?
© 2025 All rights reserved
, 3 | Page
a) 7.3
b) 6.3
c) 3.3
d) 4.3 Ans: 4.3 cubic yards
4.3 cubic yards
4inches ---> 0.333ft
Cubic feet to cubic yards /27
16220.333=117.3333
117.3333/27 = 4.3 cubic yards
How wide should the footer be for a CMU wall?
a) equal to the width of the block
b) equal to the depth of the frostline
c) three times the width of the block
d) twice the width of the block Ans: Twice the width of the block
© 2025 All rights reserved
, 4 | Page
How does a contractor know how to fill a trench to a certain
grade?
a) by guessing
b) the type of soil
c) by available backfill
d) the specifications Ans: The specifications
How many 8inch x 8inchx16inch concrete masonry blocks will be
required for a wall that is 8 feet 8 inches high and 104 feet long?
a) 936
b) 1088
c) 1124
d) 1014 Ans: 1014 blocks
8 feet * 12 inches = 96 inches + 8 inches = 104 inches
© 2025 All rights reserved
CR-21 Landscapes and Irrigation AZROC
Test Prep Questions and Correct Answers
What is the minimum thickness of brick for the exterior wall of a
fireplace?
a) 6 inches
b) 8 inches
c) 10 inches
d) 9 inches Ans: 8 Inches
What is 1/2 inch of accumulated organic material in a grassy area
called?
a) mulch
b) ground cover
c) stolons
d) thatch layer Ans: Thatch Layer
© 2025 All rights reserved
, 2 | Page
What should be provided as a cover for the drain tile before
installing the pond liner where subdrain is used?
a) 4 inches of pea gravel
b) screen with 1/4 inch mesh
c) a pool grate
d) 8 inches of medium sized rock Ans: 4 inches of pea gravel
How do you properly plant ground cover?
a) in a circular pattern
b) in rows, each row staggered
c) in groups of 2
d) 18 inches apart in rows Ans: In rows, each row staggered
You are going to pour a concrete pad that is 16 feet by 22 feet and
4 inches thick, how many cubic yards of concrete are needed?
© 2025 All rights reserved
, 3 | Page
a) 7.3
b) 6.3
c) 3.3
d) 4.3 Ans: 4.3 cubic yards
4.3 cubic yards
4inches ---> 0.333ft
Cubic feet to cubic yards /27
16220.333=117.3333
117.3333/27 = 4.3 cubic yards
How wide should the footer be for a CMU wall?
a) equal to the width of the block
b) equal to the depth of the frostline
c) three times the width of the block
d) twice the width of the block Ans: Twice the width of the block
© 2025 All rights reserved
, 4 | Page
How does a contractor know how to fill a trench to a certain
grade?
a) by guessing
b) the type of soil
c) by available backfill
d) the specifications Ans: The specifications
How many 8inch x 8inchx16inch concrete masonry blocks will be
required for a wall that is 8 feet 8 inches high and 104 feet long?
a) 936
b) 1088
c) 1124
d) 1014 Ans: 1014 blocks
8 feet * 12 inches = 96 inches + 8 inches = 104 inches
© 2025 All rights reserved
