If a + b = 1, find the value of a3 + b3 - ab - (a2 - b2)2. from

Subject

Quantitative Aptitude

Class

SSCCGL Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

61.

The average of five consecutive positive integers is n. If the next two integers are also included, the average of all these integers will

  • increase by 1.5

  • increase by 1

  • remain the same

  • remain the same

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62.

If a hemisphere is melted and four spheres of equal volume are made, the radius of each sphere will be equal to

  • 1 fourthth of the radius of the hemisphere
  • radius of the hemisphere

  • 1 half of the radius of the hemisphere
  • 1 half of the radius of the hemisphere
231 Views

63.

If a shopkeeper wants to give 20% discount on a toy, he has to sell it for Rs.300. If he sells it at Rs. 405, then his gain percent is

  • 5%

  • 4%

  • 8%

  • 8%

477 Views

64.

The average age of 30 students of a class is 14 years 4 months. After admission of 5 new students in the class the average becomes 13 years 9 months. The youngest one of the five new students is 9 years 11 months old. The average age of the remaining 4 new students is

  • 11 years 2 months

  • 13 years 6 months

  • 12 years 4 months

  • 12 years 4 months

721 Views

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65.

AD is perpendicular to the internal bisector of angle BAC of Δ ABC. DE is drawn through D and Parallel to BC to meet AC at E. If the length of AC is 12 cm, then the length of AE (in cm.) is

  • 3

  • 8

  • 4

  • 4

1100 Views

66.

The unit digit in the product (2467)153 x (341)172 is

  • 7

  • 8

  • 4

  • 4

263 Views

67.

There is a wooden sphere of radius 6 square root of 3 space cm. The surface area of the largest possible cube cut out from the sphere will be

  • 864 cm2

  • 464 square root of 3 space cm squared
  • 462 cm2

  • 462 cm2

255 Views

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68.

If a + b = 1, find the value of a3 + b3 - ab - (a2 - b2)2.

  • -1

  • 1

  • 0

  • 0


C.

0

straight a cubed space plus space straight b cubed space minus space ab space minus left parenthesis straight a squared minus straight b squared right parenthesis squared
space equals space left parenthesis straight a space plus space straight b right parenthesis thin space left parenthesis straight a squared minus ab plus straight b squared right parenthesis minus ab minus left parenthesis straight a plus straight b right parenthesis squared left parenthesis straight a minus straight b right parenthesis squared
equals space left parenthesis straight a squared minus 2 ab plus straight b squared right parenthesis minus left parenthesis straight a minus straight b right parenthesis squared space equals space left parenthesis straight a minus straight b right parenthesis squared minus left parenthesis straight a minus straight b right parenthesis squared space equals space 0
space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space open square brackets because space space straight a space plus space straight b space equals space 1 close square brackets
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69.

If 7 space sin squared straight theta space plus space 3 cos squared straight theta space equals space 4, then the value of tan θ is (θ is acute)

  • fraction numerator 1 over denominator square root of 3 end fraction
  • fraction numerator 1 over denominator square root of 2 end fraction
  • square root of 3
  • square root of 3
155 Views

70.

A cylinder with base radius 8 cm and height 2cm is melted to form a cone of height 6 cm. The radius of the cone will be

  • 6 cm

  • 8 cm

  • 4 cm

  • 4 cm

382 Views

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