0
Q:

n is an integer chosen at random from the set

{5, 7, 9, 11 }

p is chosen at random from the set

{2, 6, 10, 14, 18}

What is the probability that n + p = 23 ?

A) 0.1 B) 0.2
C) 0.25 D) 0.3

Answer:   A) 0.1



Explanation:

Each of the integers in the first set could be combined with any from the second set, giving a total of 4 x 5 = 20 possible pairs.

Of these the combinations that could give a sum of 23 are (5 + 18), and (9 + 14)

This means that the probability of getting a sum of 23 is 2/20 = 1/10

Q:

If x+1x=5, then the value of 6xx2+x+1 is,

A) 1 B) 2
C) 3 D) 4
 
Answer & Explanation Answer: A) 1

Explanation:
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2 1369
Q:

If a > b > 0, AB = a - b cm, BC = 2√ab cm, then ∠ABC is

A)  45° B)  60
C)  90° D)  120°
 
Answer & Explanation Answer: C)  90°

Explanation:
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10 2194
Q:

PR is a tangent to a circle with centre O and radius 4 cm at point Q. If ∠POR = 90°, OR = 5 cm and OP = 20/3 cm, then the length of PR is:

A) 16/3 cm B) 23/3 cm
C) 25/3 cm D) 3 cm
 
Answer & Explanation Answer: C) 25/3 cm

Explanation:
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1 1060
Q:

From a point, 40 m apart from the foot of a tower, the angle of elevation of its top is 60°. The height of the tower is

A) 40√3 km B) 40√3 cm
C) 40√3 m D) 40√2 m
 
Answer & Explanation Answer: C) 40√3 m

Explanation:
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0 1243
Q:

The radius of a sphere and hemisphere are same. The ratio of their total surface area is

A) 3:1 B)  2:1
C) 3:2 D) 4:3
 
Answer & Explanation Answer: D) 4:3

Explanation:
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0 1102
Q:

Two equal arcs of two circles subtend angle of  60° and 75° at the centre. The ratio of the radii of the two circles is

A) 5/4 B) 3/2
C) 4/5 D) 2/3
 
Answer & Explanation Answer: A) 5/4

Explanation:
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0 1504
Q:

If x + (1/x) = 2, then what is the value of x64 + x121?

A) 0 B) 1
C) 2 D) -2
 
Answer & Explanation Answer: A) 0

Explanation:
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0 891
Q:

If the diameter of a sphere is 14 cm, then what is the surface area (in sq.cm) of the sphere?

A) 616 B) 308
C) 462 D) 636
 
Answer & Explanation Answer: A) 616

Explanation:
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0 616