Expresswala Academy Mathematics Tuition

Cubes and Cube Roots

MCQ test, Set 7

  • Set 7 of 10
  • 25 questions
  • 25 marks
  • 30 minutes

Download the PDF (with key sheet and solutions, 70.2 KB)

Choose one answer for each question, then check your score at the end. Each correct answer carries 1 mark; there is no negative marking.

  1. 2×2×2×9×9×92 \times 2 \times 2 \times 9 \times 9 \times 9 can be written as
    Answer and solution

    Answer: (C) 23×932^3 \times 9^3

    Three 2's multiplied give 232^3; three 9's multiplied give 939^3.

  2. 4×4×44 \times 4 \times 4 in power form is
    Answer and solution

    Answer: (A) 434^3

    4 is multiplied by itself 3 times.

    ∴4×4×4=43\therefore 4 \times 4 \times 4 = 4^3

  3. t3t^3 means
    Answer and solution

    Answer: (B) t×t×tt \times t \times t

    The power 3 means tt is multiplied by itself 3 times.

    t3=t×t×tt^3 = t \times t \times t

  4. □3=64\square^3 = 64. The number in the box is
    Answer and solution

    Answer: (B) 44

    4×4×4=644 \times 4 \times 4 = 64

    So the box is 4.

  5. A carton has 7 layers. Each layer has 7 rows of 7 packets. How many packets are in the carton?
    Answer and solution

    Answer: (D) 343343

    Number = 7×7×77 \times 7 \times 7

    =73=343= 7^3 = 343

  6. The largest cube less than 900 is
    Answer and solution

    Answer: (C) 729729

    From the table: 93=7299^3 = 729 and 103=100010^3 = 1000

    729<900<1000729 < 900 < 1000, so the largest cube below 900 is 729.

  7. The smallest cube greater than 50 is
    Answer and solution

    Answer: (A) 6464

    From the table: 33=273^3 = 27 and 43=644^3 = 64

    27<50<6427 < 50 < 64, so the smallest cube above 50 is 64.

  8. A cube-shaped stack has 15 small cubes along each edge. The number of small cubes in it is
    Answer and solution

    Answer: (B) 33753375

    Number = 15315^3

    15×15=22515 \times 15 = 225, 225×15=3375225 \times 15 = 3375

  9. 123=144×□12^3 = 144 \times \square. The number in the box is
    Answer and solution

    Answer: (A) 1212

    123=12×12×1212^3 = 12 \times 12 \times 12 and 12×12=14412 \times 12 = 144

    ∴123=144×12\therefore 12^3 = 144 \times 12

  10. To find 16316^3, Rani first works out 16×16=25616 \times 16 = 256. What should she do next?
    Answer and solution

    Answer: (B) 256×16256 \times 16

    163=16×16×1616^3 = 16 \times 16 \times 16, so the product 256256 must be multiplied by 16 once more.

    256×16=4096256 \times 16 = 4096

  11. (−m)3=(-m)^3 =
    Answer and solution

    Answer: (D) −m3-m^3

    (−m)3=(−m)×(−m)×(−m)=−m3(-m)^3 = (-m) \times (-m) \times (-m) = -m^3

  12. Which number, multiplied by itself 3 times, gives −216-216?
    Answer and solution

    Answer: (D) −6-6

    (−6)3=−63=−216(-6)^3 = -6^3 = -216

  13. (−8)3=−□(-8)^3 = -\square. The number in the box is
    Answer and solution

    Answer: (C) 512512

    (−8)3=−83=−512(-8)^3 = -8^3 = -512

    So the box is 512.

  14. 53+53=5^3 + 5^3 =
    Answer and solution

    Answer: (B) 250250

    53+53=125+1255^3 + 5^3 = 125 + 125

    =250= 250

  15. 13+53=1^3 + 5^3 =
    Answer and solution

    Answer: (D) 126126

    13+53=1+1251^3 + 5^3 = 1 + 125

    =126= 126

  16. The sum of the cubes of 4 and 6 is
    Answer and solution

    Answer: (A) 280280

    43+63=64+2164^3 + 6^3 = 64 + 216

    =280= 280

  17. 63+(−1)3=6^3 + (-1)^3 =
    Answer and solution

    Answer: (C) 215215

    63+(−1)3=216+(−1)6^3 + (-1)^3 = 216 + (-1)

    =216−1= 216 - 1

    =215= 215

  18. (−2)3+(−6)3=(-2)^3 + (-6)^3 =
    Answer and solution

    Answer: (A) −224-224

    (−2)3+(−6)3=−8+(−216)(-2)^3 + (-6)^3 = -8 + (-216)

    =−8−216= -8 - 216

    =−224= -224

  19. (−1)3+53+(−3)3=(-1)^3 + 5^3 + (-3)^3 =
    Answer and solution

    Answer: (A) 9797

    (−1)3+53+(−3)3=−1+125+(−27)(-1)^3 + 5^3 + (-3)^3 = -1 + 125 + (-27)

    =−1+125−27= -1 + 125 - 27

    =97= 97

  20. 103−63=10^3 - 6^3 =
    Answer and solution

    Answer: (C) 784784

    103−63=1000−21610^3 - 6^3 = 1000 - 216

    =784= 784

  21. What must be added to 333^3 to get 636^3?
    Answer and solution

    Answer: (B) 189189

    Required number = 63−336^3 - 3^3

    63−33=216−276^3 - 3^3 = 216 - 27

    =189= 189

  22. By how much is 535^3 greater than 333^3?
    Answer and solution

    Answer: (C) 9898

    Difference = 53−335^3 - 3^3

    53−33=125−275^3 - 3^3 = 125 - 27

    =98= 98

  23. (−1)3−(−4)3=(-1)^3 - (-4)^3 =
    Answer and solution

    Answer: (B) 6363

    (−1)3−(−4)3=−1−(−64)(-1)^3 - (-4)^3 = -1 - (-64)

    =−1+64= -1 + 64

    =63= 63

  24. −13−83=-1^3 - 8^3 =
    Answer and solution

    Answer: (D) −513-513

    −13−83=−1−512-1^3 - 8^3 = -1 - 512

    =−513= -513

  25. (−2)3×33=(-2)^3 \times 3^3 =
    Answer and solution

    Answer: (D) −216-216

    (−2)3=−8(-2)^3 = -8, 33=273^3 = 27

    (−8)×27=−216(-8) \times 27 = -216