If x2 + 5x + 6 =  0,   then the value of &nbs

Subject

Quantitative Aptitude

Class

SSCCGL Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

51.

A can do a piece of work in 20 days and B in 15 days. With help of C, they finish the work in 5 days. C can alone do the work in

  • 5 days

  • 6 days

  • 10 days

  • 12 days

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52.

A spherical lead ball of radius 6 cm is melted and small lead balls of radius 3 mm are made. The total number of possible small lead balls is:

  • 4250

  • 4000

  • 8005

  • 8000

80 Views

53.

At what percentage above the cost price must an article be marked so as to gain 33% after allowing a customer a discount of 5%?

  • 40%

  • 45%

  • 35%

  • 47%

62 Views

54.

The four sides of a quadrilateral are in the  ratio of 2 : 3 : 4 : 5 and its perimeter is 280 m. The length of the longest side is:

  • 100 m

  • 150 m

  • 175 m

  • 180 m

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55.

Kamal has some apples. He sold 40% more than he ate. If he sold 70 apples, how many did he eat?

  • 18

  • 42

  • 50

  • 90

104 Views

56.

A train 100 m long is running at a speed of 120 km/hr. The time taken to pass a person standing near the lines is

  • 1 sec

  • 3 sec

  • 5 sec

  • 7 sec

52 Views

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57.

If x2 + 5x + 6 =  0,   then the value of fraction numerator 2 straight x over denominator straight x squared minus 7 straight x plus 6 end fraction is:

  • 1 over 6

  • 1 third

  • negative 1 over 6

  • negative 1 third


C.

negative 1 over 6

x2 + 5x+ 6 
Divide the whole equation by x:
  rightwards double arrow space space straight x space space plus space 5 space plus space 6 over straight x space equals space 0
rightwards double arrow space space space straight x space plus space 6 over straight x space equals space minus 5 space space space space space space space space space... left parenthesis straight i right parenthesis

fraction numerator 2 straight x over denominator straight x squared minus 7 straight x plus 6 end fraction
Again divide the whole equation by x:
rightwards double arrow space space fraction numerator 2 over denominator straight x minus 7 plus begin display style 6 over straight x end style end fraction
space equals space fraction numerator 2 over denominator straight x plus begin display style 6 over straight x end style minus 7 end fraction
equals space fraction numerator 2 over denominator negative 5 minus 7 end fraction space equals space fraction numerator negative 2 over denominator 12 end fraction space equals space minus 1 over 6 space space space left square bracket Using space left parenthesis straight i right parenthesis right square bracket



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58.

If a + b = 5   and   a - b = 3, then the value of (a2 + b2) is

  • 17

  • 18

  • 19

  • 20

54 Views

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59.

A 8 cm long perpendicular is drawn from the centre of a circle to a 12cm long chord. The diameter of the circle is

  • 10 cm

  • 12 cm

  • 16 cm

  • 20 cm

55 Views

60.

The point equidistant from the sides of a triangle is called:

  • Circumcenter

  • Incentre

  • Orthocentre

  • Centroid

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