Expresswala Academy Mathematics Tuition

Understanding Integers

MCQ test, Set 9

  • Set 9 of 10
  • 25 questions
  • 25 marks
  • 30 minutes

Download the PDF (with key sheet and solutions, 73.5 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. Starting at 66, Anil makes 1212 jumps of 11 to the left on the number line. Anil lands on
    Answer and solution

    Answer: (B) −6-6

    Jumps to the left subtract.

    6−12=−(12−6)=−66 - 12 = -(12 - 6) = -6

  2. The number of integers between −10-10 and 1515 is
    Answer and solution

    Answer: (D) 2424

    Between −10-10 and 00: 99; then 00 itself; between 00 and 1515: 1414.

    Total =9+1+14=24= 9 + 1 + 14 = 24

  3. The value of −77−79-77 - 79 is
    Answer and solution

    Answer: (A) −156-156

    Both are negative: add and keep the −- sign.

    −77−79=−(77+79)=−156-77 - 79 = -(77 + 79) = -156

  4. The sum of −98-98 and −64-64 is
    Answer and solution

    Answer: (D) −162-162

    Adding −64-64 to −98-98 gives −98−64-98 - 64.

    Both are negative: −98−64=−(98+64)=−162-98 - 64 = -(98 + 64) = -162

  5. In −32+25=−(□)-32 + 25 = -(\square), the number in the box is
    Answer and solution

    Answer: (C) 77

    Different signs: subtract the smaller from the bigger; the bigger is negative, so the answer is negative.

    −32+25=−(32−25)=−(7)-32 + 25 = -(32 - 25) = -(7)

  6. −86+69=-86 + 69 =
    Answer and solution

    Answer: (C) −17-17

    Different signs: subtract the smaller from the bigger and keep the sign of the bigger.

    −86+69=−(86−69)=−17-86 + 69 = -(86 - 69) = -17

  7. The sum of 4747 and −83-83 is
    Answer and solution

    Answer: (B) −36-36

    This is 47−8347 - 83.

    47−83=−(83−47)=−3647 - 83 = -(83 - 47) = -36

  8. A trader gained ₹2663 on one deal and lost ₹3016 on another. Altogether this is
    Answer and solution

    Answer: (C) a loss of ₹353

    Gain =+2663= +2663, loss =−3016= -3016

    2663−3016=−(3016−2663)=−3532663 - 3016 = -(3016 - 2663) = -353

    A loss of ₹353.

  9. The value of −8187+6189-8187 + 6189 is
    Answer and solution

    Answer: (A) −1998-1998

    Different signs: subtract and keep the sign of the bigger number.

    −8187+6189=−(8187−6189)=−1998-8187 + 6189 = -(8187 - 6189) = -1998

  10. Subtract 85748574 from 8810188101. The answer is
    Answer and solution

    Answer: (C) 7952779527

    Subtract column by column from the units, borrowing where the top digit is smaller.

    88101−8574=7952788101 - 8574 = 79527

  11. Divya worked out 74324−325874324 - 3258 and got 7113471134, which is wrong. The correct answer is
    Answer and solution

    Answer: (A) 7106671066

    Subtract column by column from the units. When you borrow, take the 11 away from the next column.

    74324−3258=7106674324 - 3258 = 71066

  12. To find 702−494702 - 494, Arjun counts down 702→500→494702 \to 500 \to 494. The two jumps are
    Answer and solution

    Answer: (D) 202202 and 66

    702→500702 \to 500: 702−500=202702 - 500 = 202

    500→494500 \to 494: 500−494=6500 - 494 = 6

    (So 702−494=202+6=208702 - 494 = 202 + 6 = 208.)

  13. 559−727=559 - 727 =
    Answer and solution

    Answer: (D) −168-168

    559−727=−(727−559)559 - 727 = -(727 - 559)

    727→600→559727 \to 600 \to 559: 127+41=168127 + 41 = 168

    So the answer is −168-168

  14. 6012−356−7607=6012 - 356 - 7607 =
    Answer and solution

    Answer: (A) −1951-1951

    Positive term: 60126012

    Negative terms: 356+7607=7963356 + 7607 = 7963

    6012−356−7607=6012−79636012 - 356 - 7607 = 6012 - 7963 =−(7963−6012)=−1951= -(7963 - 6012) = -1951

  15. In 714+322−245−43714 + 322 - 245 - 43, the total of the positive terms and the total of the negative terms (without the sign) are
    Answer and solution

    Answer: (D) 10361036 and 288288

    Positive terms: 714+322=1036714 + 322 = 1036

    Negative terms: 245+43=288245 + 43 = 288

  16. 906−15+381−751=906 - 15 + 381 - 751 =
    Answer and solution

    Answer: (D) 521521

    Add the positive terms, add the negative terms, then subtract.

    906−15+381−751=1287−766906 - 15 + 381 - 751 = 1287 - 766 =521= 521

  17. Without working it out, the product −84×42-84 \times 42 is
    Answer and solution

    Answer: (B) negative

    −×+=−- \times + = -

    So the product is negative.

  18. 43×−643 \times -6 equals
    Answer and solution

    Answer: (A) −258-258

    Sign: +×−=−+ \times - = -

    43×6=25843 \times 6 = 258, so 43×−6=−25843 \times -6 = -258

  19. Which of these equals 132132?
    Answer and solution

    Answer: (B) −4×−33-4 \times -33

    −4×−33-4 \times -33: −×−=+- \times - = +, so it is 132132

    The others are all −132-132: −3×44-3 \times 44 is −×+- \times +, and the two additions give −(78+54)-(78 + 54) and −(135−3)-(135 - 3).

  20. −436×48=-436 \times 48 =
    Answer and solution

    Answer: (A) −20928-20928

    Sign: −×+=−- \times + = -

    436×8=3488436 \times 8 = 3488, 436×40=17440436 \times 40 = 17440, 3488+17440=209283488 + 17440 = 20928

    So −436×48=−20928-436 \times 48 = -20928

  21. The value of −83×−99-83 \times -99 is
    Answer and solution

    Answer: (B) 82178217

    Sign: −×−=+- \times - = +

    99×3=29799 \times 3 = 297, 99×80=792099 \times 80 = 7920, 297+7920=8217297 + 7920 = 8217

    So −83×−99=8217-83 \times -99 = 8217

  22. −625866=\displaystyle \frac{-62586}{6} =
    Answer and solution

    Answer: (C) −10431-10431

    −+=−\displaystyle \frac{-}{+} = -

    6÷6=16 \div 6 = 1; 2÷6=02 \div 6 = 0 r 22; 25÷6=425 \div 6 = 4 r 11; 18÷6=318 \div 6 = 3; 6÷6=16 \div 6 = 1

    So −625866=−10431\displaystyle \frac{-62586}{6} = -10431

  23. Only one of these is positive. Which one?
    Answer and solution

    Answer: (C) −468−9\displaystyle \frac{-468}{-9}

    −−=+\displaystyle \frac{-}{-} = + while +−\displaystyle \frac{+}{-} and −+\displaystyle \frac{-}{+} are −-.

    −468−9=52\displaystyle \frac{-468}{-9} = 52

  24. Which of these equals 4545?
    Answer and solution

    Answer: (A) −135−3\displaystyle \frac{-135}{-3}

    −135−3\displaystyle \frac{-135}{-3}: −−=+\displaystyle \frac{-}{-} = + and 135÷3=45135 \div 3 = 45

    The others are all −45-45: −×+- \times +, two negatives added, and +−\displaystyle \frac{+}{-}.

  25. −48+6=-48 + 6 =
    Answer and solution

    Answer: (A) −42-42

    This is addition with different signs, not multiplication.

    −48+6=−(48−6)=−42-48 + 6 = -(48 - 6) = -42