Expresswala Academy Mathematics Tuition

Cubes and Cube Roots

MCQ test, Set 2

  • Set 2 of 10
  • 25 questions
  • 25 marks
  • 30 minutes

Download the PDF (with key sheet and solutions, 75.7 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. 5×5×5=5□5 \times 5 \times 5 = 5^{\square}. The number in the box is
    Answer and solution

    Answer: (D) 33

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

    5×5×5=535 \times 5 \times 5 = 5^3

  2. In t3t^3, the small 3 tells us that
    Answer and solution

    Answer: (A) tt is multiplied by itself 3 times

    t3=t×t×tt^3 = t \times t \times t: three tt's are multiplied.

  3. m×m×m×n×n×nm \times m \times m \times n \times n \times n in power form is
    Answer and solution

    Answer: (A) m3×n3m^3 \times n^3

    m×m×m=m3m \times m \times m = m^3 and n×n×n=n3n \times n \times n = n^3

    So it is m3×n3m^3 \times n^3.

  4. 300 lies between
    Answer and solution

    Answer: (D) 636^3 and 737^3

    63=2166^3 = 216 and 73=3437^3 = 343

    216<300<343216 < 300 < 343

  5. Which of these is NOT a cube?
    Answer and solution

    Answer: (C) 6060

    27=3327 = 3^3, 125=53125 = 5^3, 343=73343 = 7^3.

    60 is not in the table of cubes.

  6. A carton has 9 layers. Each layer has 9 rows of 9 packets. How many packets are in the carton?
    Answer and solution

    Answer: (B) 729729

    Number = 9×9×99 \times 9 \times 9

    =93=729= 9^3 = 729

  7. The largest cube less than 500 is
    Answer and solution

    Answer: (B) 343343

    From the table: 73=3437^3 = 343 and 83=5128^3 = 512

    343<500<512343 < 500 < 512, so the largest cube below 500 is 343.

  8. A big cube is built from small cubes, with 11 small cubes along each edge. How many small cubes does it have?
    Answer and solution

    Answer: (C) 13311331

    Number = 11311^3

    11×11=12111 \times 11 = 121, 121×11=1331121 \times 11 = 1331

  9. 133=169×□13^3 = 169 \times \square. The number in the box is
    Answer and solution

    Answer: (B) 1313

    133=13×13×1313^3 = 13 \times 13 \times 13 and 13×13=16913 \times 13 = 169

    ∴133=169×13\therefore 13^3 = 169 \times 13

  10. To find 17317^3, Rani first works out 17×17=28917 \times 17 = 289. What should she do next?
    Answer and solution

    Answer: (D) 289×17289 \times 17

    173=17×17×1717^3 = 17 \times 17 \times 17, so the product 289289 must be multiplied by 17 once more.

    289×17=4913289 \times 17 = 4913

  11. (−10)3=−□(-10)^3 = -\square. The number in the box is
    Answer and solution

    Answer: (C) 10001000

    (−10)3=−103=−1000(-10)^3 = -10^3 = -1000

    So the box is 1000.

  12. (−12)×(−12)×(−12)=(-12) \times (-12) \times (-12) =
    Answer and solution

    Answer: (B) −1728-1728

    (−12)×(−12)=144(-12) \times (-12) = 144

    144×(−12)=−1728144 \times (-12) = -1728

  13. (−30)3=(-30)^3 =
    Answer and solution

    Answer: (C) −27000-27000

    (−30)×(−30)=900(-30) \times (-30) = 900

    900×(−30)=−27000900 \times (-30) = -27000

  14. Two big cubes are made of small cubes, with 3 and 4 small cubes along each edge. How many small cubes are there in the two cubes together?
    Answer and solution

    Answer: (D) 9191

    Total = 33+433^3 + 4^3

    33+43=27+643^3 + 4^3 = 27 + 64

    =91= 91

  15. 13+23+43=1^3 + 2^3 + 4^3 =
    Answer and solution

    Answer: (D) 7373

    13+23+43=1+8+641^3 + 2^3 + 4^3 = 1 + 8 + 64

    =73= 73

  16. The sum of the cubes of 1 and 8 is
    Answer and solution

    Answer: (B) 513513

    13+83=1+5121^3 + 8^3 = 1 + 512

    =513= 513

  17. (−1)3+23+(−3)3=(-1)^3 + 2^3 + (-3)^3 =
    Answer and solution

    Answer: (A) −20-20

    (−1)3+23+(−3)3=−1+8+(−27)(-1)^3 + 2^3 + (-3)^3 = -1 + 8 + (-27)

    =−1+8−27= -1 + 8 - 27

    =−20= -20

  18. 63+(−4)3=6^3 + (-4)^3 =
    Answer and solution

    Answer: (A) 152152

    63+(−4)3=216+(−64)6^3 + (-4)^3 = 216 + (-64)

    =216−64= 216 - 64

    =152= 152

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

    Answer: (D) −72-72

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

    =−8−64= -8 - 64

    =−72= -72

  20. By how much is 838^3 greater than 636^3?
    Answer and solution

    Answer: (D) 296296

    Difference = 83−638^3 - 6^3

    83−63=512−2168^3 - 6^3 = 512 - 216

    =296= 296

  21. One big cube has 6 small cubes along each edge and another has 5. How many more small cubes does the first one have?
    Answer and solution

    Answer: (A) 9191

    More = 63−536^3 - 5^3

    63−53=216−1256^3 - 5^3 = 216 - 125

    =91= 91

  22. Ravi says 23−73=3352^3 - 7^3 = 335. The correct value is
    Answer and solution

    Answer: (A) −335-335

    23−73=8−3432^3 - 7^3 = 8 - 343

    =−335= -335

    Ravi took the smaller cube from the bigger one.

  23. 103÷23=10^3 \div 2^3 =
    Answer and solution

    Answer: (C) 125125

    103=100010^3 = 1000, 23=82^3 = 8

    1000÷8=1251000 \div 8 = 125

  24. If x=−3x = -3 and y=2y = 2, then x3+y3=x^3 + y^3 =
    Answer and solution

    Answer: (C) −19-19

    (−3)3+23=−27+8(-3)^3 + 2^3 = -27 + 8

    =−19= -19

  25. (−3)3−(−5)3=(-3)^3 - (-5)^3 =
    Answer and solution

    Answer: (B) 9898

    (−3)3−(−5)3=−27−(−125)(-3)^3 - (-5)^3 = -27 - (-125)

    =−27+125= -27 + 125

    =98= 98