In a family of 3 children, the probability of having at least one

Subject

Mathematics

Class

CBSE Class 10

Pre Boards

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Sample Papers

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 Multiple Choice QuestionsMultiple Choice Questions

1.

The probability that a number selected at random from the numbers 1, 2, 3, ..., 15 isa multiple of 4, is

  • 415

  • 212

  • 15

  • 13


2.

Two circles touch each other externally at P. AB is a common tangent to the circlestouching them at A and B. The value of ∠APB is

  • 30°

  • 45°

  • 60°

  • 90°


3.

If k, 2k- 1 and 2k + 1 are three consecutive terms of an A.P., the value of k is

  • 2

  • 3

  • -3

  • 5


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4.

In a family of 3 children, the probability of having at least one boy is

  • 78

  • 18

  • 58

  • 34


A.

78

There are in all 23 = 8 combinations or outcomes for the gender of the 3 children

The 8 combinations are as follows

BBB, BBG, BGB, BGG, GBB, GBG, GGB, GGG

Thus the probability of having at least one boy in a family is 78

 


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5.

A chord of a circle of radius 10 cm subtends a right angleat its centre. The length of the chord (in cm) is

  • 52

  • 102

  • 52

  • 103


6.

ABCD is a rectangle whose three vertices are B (4, 0), C(4,3) and D(0, 3). The length of one of its diagonals is

  • 5

  • 4

  • 3

  • 25


7.

The angle of depression of a car parked on the road from the top of a 150 m high tower is 30°. The distance of the car from the tower (in metres) is

  • 503

  • 1503

  • 1502

  • 75


8.

In a right triangle ABC, right-angled at B, BC = 12 cm and AB = 5 cm. The radius of the circle inscribed in the triangle (in cm) is

  • 4

  • 3

  • 2

  • 1


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 Multiple Choice QuestionsShort Answer Type

9.

The incircle of an isosceles triangle ABC, in which AB = AC, touches the sides BC, CA and AB at D, E and F respectively. Prove that BD = DC.


10.

Two different dice are tossed together. Find the probability

(i) That the number on each die is even.

(ii) That the sum of numbers appearing on the two dice is 5.


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