Subject

Mathematics

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
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 Multiple Choice QuestionsLong Answer Type

31.

Using integration, find the area of the region bounded by the triangle whose vertices are (-1, 2), (1, 5) and (3, 4).

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32.

A manufacturing company makes two types of teaching aids A and B of Mathematics for class XII. Each type of A requires 9 labour hours of fabricating and 1 labour hour for finishing. Each type of B requires 12 labour hours for fabricating and 3 labour hours for finishing. For fabricating and finishing, the maximum labour hours available per week are 180 and 30 respectively. The company makes a profit of 80 on each piece of type A and 120 on each piece of type B. How many pieces of type A and type B should be manufactured per week to get a maximum profit? Make it as an LPP and solve graphically. What is the maximum profit per week?

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33.

There are three coins. One is a two-headed coin (having head on both faces), another is a biased coin that comes up heads 75% of the times and third is also a biased coin that comes up tails 40% of the times. One of The three coins is chosen at random and tossed, and it shows heads. What is the probability that it was the two-headed coin?


Let space straight E subscript 1 comma space straight E subscript 2 comma space straight E subscript 3 space and space straight A space be space the space events space defined space as space follows colon
straight E subscript 1 equals space space Choosing space 2 space headed space coin
straight E subscript 2 equals Choosing space coin space with space 75 percent sign space chance space of space getting space heads
straight E subscript 3 equals Choosing space coin space with space 40 percent sign space chance space of space getting space heads
straight A space equals space Getting space heads
Then space straight P left parenthesis straight E subscript 1 right parenthesis space equals space straight P left parenthesis straight E subscript 2 right parenthesis space equals space straight P left parenthesis straight E subscript 3 right parenthesis space equals space 1 third
Also comma space straight P left parenthesis straight A divided by straight E subscript 1 right parenthesis space equals space 1 comma space space straight P left parenthesis straight A divided by straight E subscript 2 right parenthesis space equals space 75 over 100 equals 3 over 4 comma space space straight P left parenthesis straight A divided by straight E subscript 3 right parenthesis space equals space 40 over 100 equals 2 over 5
Required space Probability
equals straight P left parenthesis straight E subscript 1 divided by straight A right parenthesis
equals space fraction numerator straight P left parenthesis straight E subscript 1 right parenthesis thin space straight P left parenthesis straight A divided by straight E subscript 1 right parenthesis right parenthesis over denominator straight P left parenthesis straight E subscript 1 right parenthesis space straight P left parenthesis straight A divided by straight E subscript 1 right parenthesis plus straight P left parenthesis straight E subscript 2 right parenthesis thin space straight P left parenthesis straight A divided by straight E subscript 2 right parenthesis plus straight P left parenthesis straight E subscript 3 right parenthesis space straight P left parenthesis straight A divided by straight E subscript 3 right parenthesis end fraction
equals fraction numerator begin display style 1 third end style cross times 1 over denominator begin display style 1 third end style cross times 1 plus begin display style 1 third end style cross times begin display style 3 over 4 end style plus begin display style 1 third end style cross times begin display style 2 over 5 end style end fraction
equals space fraction numerator begin display style 1 third end style over denominator begin display style 1 third end style plus begin display style 1 fourth end style plus begin display style 2 over 15 end style end fraction
equals fraction numerator begin display style 1 third end style over denominator begin display style 43 over 60 end style end fraction space equals 1 over 860
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34.

Two numbers are selected at random (without replacement) from the first six positive integers. Let X denote the larger of the two numbers obtained. Find the probability distribution of the random variable X, and hence find the mean of the distribution.

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35.

Evaluate:
integral fraction numerator 1 over denominator sin to the power of 4 straight x plus sin squared xcos squared straight x plus cos to the power of 4 straight x end fraction dx

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