If  then the value of a3 + b3 - 2 is from Quantitative Aptitu

Subject

Quantitative Aptitude

Class

SSCCGL Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

51.

If 35 men finish a piece of work in 8 days, then the number of men who can do the same work in 10 days is

  • 38

  • 28

  • 19

  • 19

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52.

A shopkeeper gives two successive discounts of 7% each on marked price of ₹ 20,000/- of an article. The selling price of the article is

  • ₹ 12,798
  • ₹ 19,278

  • ₹ 18,927

  • ₹ 18,927

54 Views

53.

The present ages of A and B are in the ratio 3 : 4. Ten years ago, this ratio was 4 : 7. The present age of A and B are respectively:

  • 18 years, 24 years

  • 21 years, 28 years

  • 24 years, 32 years

  • 24 years, 32 years

78 Views

54.

Sapna purchased a cycle for ₹ 1,000/- and sold it for ₹ 1,200/-. Her gain in percentage is

  • 20%

  • 10%

  • 12%

  • 12%

48 Views

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55.

In 2001, the price of a building was 80% of its original price. In 2002, the price was 60% of its original price. By what percent did the price decrease?

  • 15%

  • 20%

  • 25%

  • 25%

75 Views

56.

Sound travels 330 m in a second. When the sound follows the flash of lightning after 10 sec, the thunder cloud will be at a distance of

  • 1300 m

  • 2000 m

  • 3650 m

  • 3650 m

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57.

If straight a over straight b space plus space straight b over straight a space equals space 1 comma then the value of a3 + b3 - 2 is

  • 0

  • -2

  • -1

  • -1


B.

-2

rightwards double arrow space space space straight a over straight b plus straight b over straight a space equals space 1
rightwards double arrow space space fraction numerator straight a squared plus straight b squared over denominator ab end fraction space equals space 1
rightwards double arrow space space space straight a squared space plus space straight b squared space minus ab space equals space 0
As,
 a3 + b3 = (a +b) (a2 + b2 - ab)
 a3 + b3 = (a + b) x 0
 a3 + b3 = 0
∴    a3 + b- 2 = 0 - 2 = -2 

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58.

The amount to be paid, when principal  = ₹ 2,000/-, Rate of simple interest (R) = 5%, T = 2 years, is

  • ₹ 3,200/-
  • ₹ 2,400/-
  • ₹ 2,200/-
  • ₹ 2,200/-
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59.

If x + y = 1 + xy, then x3 + y3 - x3y3 is equal to

  • 0

  • 1

  • -1

  • -1

69 Views

60.

The perimeter of two similar triangles ΔABC and ΔPQR are 60 cm and 36 cm respectively. If PQ = 18 cm, then AB is

  • 20 cm

  • 24 cm

  • 36 cm

  • 36 cm

114 Views

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