1 .Bisectors of two adjacent angles Aand Bof a quadrilateral ABCDintersect each other at a point P. Which one of the following is correct ?
Answer & Explanation
Answer : Option A |
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Explanation : |
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2 .
Answer & Explanation
Answer : Option B |
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Explanation : |
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3 .The diameter of two circles are 18 cm and 8 cm. The distance between their centres is 13 cm. What is the number of common tangents?
Answer & Explanation
Answer : Option C |
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Explanation : |
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Here, r1 = 9 cm and r 2 = 4 cm
r 1 + r 2 = 9 + 4 = 13 cm
and r 1 – r 2 = 9 – 4 = 5cm
Also, d = 13 cm
Here, d = r 1 + r 2
= 13 cm
Hence, two circles touch each other externally, so three total no of common tangents are three. |
4 .What is the geometric means of the observations 125, 729, 1331?
Answer & Explanation
Answer : Option A |
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Explanation : |
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G.M. = $3\sqrt{125 X 729 X 1331}$ = $3\sqrt{5^3 X 9^3 X 11^3}$ = 5 × 9 × 11 = 495 |
5 .The mean of 100 values is 45. If 15 is added to each of the first forty values and 5 is subtracted from each of the remaining sixty values, the new mean becomes
Answer & Explanation
Answer : Option B |
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Explanation : |
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6 .A cylindrical tube open at both ends is made of metal. The internal diameter of the tube is 6 cm and length of the tube is 10 cm. If the thickness of the metal used is 1 cm, then the outer curved surface area of the tube is
Answer & Explanation
Answer : Option D |
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Explanation : |
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7 .For a plot of land of 100 m × 80 m, the length to be raised by spreading the earth from stack of a rectangular base 10 m × 8 m and vertical section being a trapezium of height 2 m. The top of the stack is 8 m × 5 m. How many centimeters can the level raised?
Answer & Explanation
Answer : Option D |
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Explanation : |
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The stack is in the form having vertical cross section of trapezium.
∴ Volume of Earth in the stack = Area of cross section
of trapezium × Height
∴ Volume = $1\over2$(10+5) x 2 x 8 = 15 x 8 $m^2$ According to the question,
Volume of Earth to be spread = (Area of field) × Level raised
∴ Level raised =$15X8\over100X80$ = $15\over1000$ m= 1.5cm |
8 .If $3^x$ x + 27($3^-x$) = 12, then what is the value of x?
Answer & Explanation
Answer : Option C |
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Explanation : |
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9 .For which value of k does the pair of equations $x^2-y^2$ = 0 and $(x– k)^2$ + $y^2$ = 1 yield a unique positive solution of x?
(a).2
(b).0
(c)$ \sqrt{2}$
(d)$-\sqrt{2}$
Answer & Explanation
Answer : Option A |
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Explanation : |
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10 .The expression $sin^2$ x + $cos^2$ x-1=0 is satisfied by how many values of x?
Answer & Explanation
Answer : Option C |
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Explanation : |
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Given that, $sin^2$ x + $cos^2$ x-1=0
==> $sin^2$ x + $cos^2$x=1
which is an identity of trigonometric ratio and always true for every real value of x. Therefore, the equation has an infinite solution. |
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