Expresswala Academy Mathematics Tuition

Cubes and Cube Roots

MCQ test, Set 10

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

Download the PDF (with key sheet and solutions, 71.4 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. 9×9×9=9□9 \times 9 \times 9 = 9^{\square}. The number in the box is
    Answer and solution

    Answer: (A) 33

    9 is multiplied by itself 3 times, so the power is 3.

    9×9×9=939 \times 9 \times 9 = 9^3

  2. x×x×x×y×y×yx \times x \times x \times y \times y \times y in power form is
    Answer and solution

    Answer: (A) x3×y3x^3 \times y^3

    x×x×x=x3x \times x \times x = x^3 and y×y×y=y3y \times y \times y = y^3

    So it is x3×y3x^3 \times y^3.

  3. c3c^3 means
    Answer and solution

    Answer: (B) c×c×cc \times c \times c

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

    c3=c×c×cc^3 = c \times c \times c

  4. How many cubes of whole numbers lie between 200 and 800?
    Answer and solution

    Answer: (C) 44

    From the table of cubes, the cubes between 200 and 800 are 216216, 343343, 512512, 729729.

    That is 4 cubes.

  5. Which of these can be written as k3k^3 for a whole number kk?
    Answer and solution

    Answer: (C) 729729

    729=9×9×9=93729 = 9 \times 9 \times 9 = 9^3

    The other numbers are not in the table of cubes.

  6. The next number in 64,125,216,343,…64, 125, 216, 343, \ldots is
    Answer and solution

    Answer: (D) 512512

    These are 434^3, 535^3, 636^3, 737^3.

    Next is 83=5128^3 = 512

  7. How many small cubes make a big cube that has 7 small cubes along each edge?
    Answer and solution

    Answer: (A) 343343

    Each layer has 7×77 \times 7 cubes and there are 7 layers.

    Number = 73=3437^3 = 343

  8. 213=21^3 =
    Answer and solution

    Answer: (B) 92619261

    21×21=44121 \times 21 = 441

    441×21=9261441 \times 21 = 9261

  9. To find 12312^3, Rani first works out 12×12=14412 \times 12 = 144. What should she do next?
    Answer and solution

    Answer: (C) 144×12144 \times 12

    123=12×12×1212^3 = 12 \times 12 \times 12, so the product 144144 must be multiplied by 12 once more.

    144×12=1728144 \times 12 = 1728

  10. 163=256×□16^3 = 256 \times \square. The number in the box is
    Answer and solution

    Answer: (B) 1616

    163=16×16×1616^3 = 16 \times 16 \times 16 and 16×16=25616 \times 16 = 256

    ∴163=256×16\therefore 16^3 = 256 \times 16

  11. (−16)×(−16)×(−16)=(-16) \times (-16) \times (-16) =
    Answer and solution

    Answer: (D) −4096-4096

    (−16)×(−16)=256(-16) \times (-16) = 256

    256×(−16)=−4096256 \times (-16) = -4096

  12. (−t)3=(-t)^3 =
    Answer and solution

    Answer: (B) −t3-t^3

    (−t)3=(−t)×(−t)×(−t)=−t3(-t)^3 = (-t) \times (-t) \times (-t) = -t^3

  13. (−4)3=−□(-4)^3 = -\square. The number in the box is
    Answer and solution

    Answer: (D) 6464

    (−4)3=−43=−64(-4)^3 = -4^3 = -64

    So the box is 64.

  14. 103+13=10^3 + 1^3 =
    Answer and solution

    Answer: (B) 10011001

    103+13=1000+110^3 + 1^3 = 1000 + 1

    =1001= 1001

  15. 13+23+53=1^3 + 2^3 + 5^3 =
    Answer and solution

    Answer: (C) 134134

    13+23+53=1+8+1251^3 + 2^3 + 5^3 = 1 + 8 + 125

    =134= 134

  16. The sum of the cubes of 3 and 9 is
    Answer and solution

    Answer: (D) 756756

    33+93=27+7293^3 + 9^3 = 27 + 729

    =756= 756

  17. (−3)3+83=(-3)^3 + 8^3 =
    Answer and solution

    Answer: (C) 485485

    (−3)3+83=−27+512(-3)^3 + 8^3 = -27 + 512

    =485= 485

  18. (−2)3+(−7)3=(-2)^3 + (-7)^3 =
    Answer and solution

    Answer: (D) −351-351

    (−2)3+(−7)3=−8+(−343)(-2)^3 + (-7)^3 = -8 + (-343)

    =−8−343= -8 - 343

    =−351= -351

  19. 43+(−2)3=4^3 + (-2)^3 =
    Answer and solution

    Answer: (D) 5656

    43+(−2)3=64+(−8)4^3 + (-2)^3 = 64 + (-8)

    =64−8= 64 - 8

    =56= 56

  20. What must be added to 636^3 to get 737^3?
    Answer and solution

    Answer: (A) 127127

    Required number = 73−637^3 - 6^3

    73−63=343−2167^3 - 6^3 = 343 - 216

    =127= 127

  21. By how much is 10310^3 greater than 535^3?
    Answer and solution

    Answer: (C) 875875

    Difference = 103−5310^3 - 5^3

    103−53=1000−12510^3 - 5^3 = 1000 - 125

    =875= 875

  22. Ravi says 53−93=6045^3 - 9^3 = 604. The correct value is
    Answer and solution

    Answer: (A) −604-604

    53−93=125−7295^3 - 9^3 = 125 - 729

    =−604= -604

    Ravi took the smaller cube from the bigger one.

  23. −23−63=-2^3 - 6^3 =
    Answer and solution

    Answer: (B) −224-224

    −23−63=−8−216-2^3 - 6^3 = -8 - 216

    =−224= -224

  24. 23×(−3)3=2^3 \times (-3)^3 =
    Answer and solution

    Answer: (B) −216-216

    23=82^3 = 8, (−3)3=−27(-3)^3 = -27

    8×(−27)=−2168 \times (-27) = -216

  25. 153÷53=15^3 \div 5^3 =
    Answer and solution

    Answer: (A) 2727

    153=337515^3 = 3375, 53=1255^3 = 125

    3375÷125=273375 \div 125 = 27